Direct hydroperoxygenation of conjugated olefins catalyzed by cobalt(II) porphyrin

Article abstract of DOI:10.1039/a805888a

A novel and direct synthesis of hydroperoxy compounds from various types of conjugated olefins was established via cobalt(II) porphyrin-catalyzed hydroperoxygenation. The reaction of α,β,γ,δ-unsaturated carbonyl compounds, acrylic esters, α-substituted acrylic esters and styrene derivatives with molecular oxygen and triethylsilane in the presence of a catalytic amount of cobalt(II) porphyrin proceeded rapidly to give the corresponding hydroperoxygenated compounds in high or moderate yields.

Full text of DOI:10.1039/a805888a

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Direct hydroperoxygenation of conjugated olefins catalyzed by
cobalt(II) porphyrin
Kazuhiro Sugamoto,* Yoh-ichi Matsushita and Takanao Matsui
Faculty of Engineering, Miyazaki University, Gakuen-Kibanadai, Miyazaki 889-2192, Japan
E-mail: t0a304u@cc.miyazaki-u.ac.jp
Received (in Cambridge) 28th July 1998, Accepted 2nd October 1998
A novel and direct synthesis of hydroperoxy compounds from various types of conjugated olefins was established
via cobalt() porphyrin-catalyzed hydroperoxygenation. The reaction of α,β,γ,δ-unsaturated carbonyl compounds,
acrylic esters, α-substituted acrylic esters and styrene derivatives with molecular oxygen and triethylsilane in the
presence of a catalytic amount of cobalt() porphyrin proceeded rapidly to give the corresponding
hydroperoxygenated compounds in high or moderate yields.
R1
Introduction
COR2
Due to the importance of alkyl hydroperoxides in biology and
chemistry, various methods for their preparation have been
developed.1 For example, the autooxidation of alkanes, the
R
singlet oxygenation of olefins,2 the acidic addition of hydrogen
COR
X
peroxide to olefins3 and the alkylation of hydrogen peroxide
under basic conditions4 are well known, however the yields of
CoII(tdcpp)
the alkyl hydroperoxides are sometimes unsatisfactory due to
their lability. Recently, Bloodworth et al. reported a four-step
synthesis of alkyl hydroperoxides via hydroperoxymercuriation
of alkenes followed by protection with 2-methoxypropene,
reductive demercuriation, and deprotection.5 Dussault et al.
reported an efficient method for the preparation of alkenyl
hydroperoxides via Wittig or Horner–Emmons olefination of
peroxy-substituted aldehydes which are obtained by photo-
chemical oxygenation of dec-5-ene or lipoxygenase-catalyzed
aerobic oxygenation of linoleic acid followed by acetal pro-
tection and ozonolysis.6 Although these methods needed
multi-step procedures, the hydroperoxides were produced in
good yields. A direct hydroperoxygenation of aralkanes with
tert-butyl hydroperoxide using calcined ZnCrCO3–HTlc,† a
homogeneously dispersed bimetallic oxide as a hydrocarbon
activator, was described by Choudary et al., but the yields of
the alkyl hydroperoxides were low and the substrates are limited
to aralkanes.7 Mukaiyama et al. found a novel method for
preparation of alkyl triethylsilyl peroxides with molecular oxy-
gen and triethylsilane in the presence of bis(1,3-diketonato)-
cobalt() as a catalyst. The reaction took place in aprotic
solvents such as 1,2-dichloroethane and benzene, although not
in alcohols such as propan-1-ol, and had a tendency to be more
active for non-conjugated olefins such as 4-phenylbut-1-ene
than for styrene.8
PriOH - DCM
O2
Et3SiH
OOH
R1
COR2
OOH
OOH
R
COR
X
Ac2O - DMAP
(MeO)3P
O
OH
R1
R1
COR2
COR2
OH
O
O
OH
R
R
COR
COR
X
X
Scheme 1
In our previous communication, we preliminarily reported
that cobalt() porphyrin-catalyzed hydroperoxygenation of
conjugated olefins with molecular oxygen and triethylsilane in
propan-2-ol–DCM gave the corresponding hydroperoxides in
good yields.9 In addition, appropriate treatment of the inter-
mediary hydroperoxides after the hydroperoxygenation was
found to afford ketones and alcohols in one pot (Scheme 1).10–12
Although γ-hydroxy- or γ-oxo-α,β-unsaturated carbonyl com-
pounds have been synthesized by various methods,13 our
method via the hydroperoxygenation provides a novel and ver-
satile route to γ-hydroxy- or γ-oxo-α,β-unsaturated carbonyl
compounds and is easily applicable to the syntheses of several
natural products.14–16 We describe herein the scope and features
of our cobalt() porphyrin-catalyzed hydroperoxygenation in
detail.
Results and discussion
Effects of catalysts and substituted silanes
Since the hydroperoxygenation of conjugated olefins catalyzed
by cobalt() porphyrin was found to proceed in a mixture of
alcohol and DCM but not in DCM from our previous work,10
we chose a 1:1 mixture of propan-2-ol and DCM as the sol-
vent. The effect of catalysts on the hydroperoxygenation was
† HTlc: Hydrotalcite-like compound.
J. Chem. Soc., Perkin Trans. 1, 1998, 3989–3998
3989

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Table 1 Reversible half-wave potentials for the oxidation of cobaltII
porphyrinsa
₁
E /V vs. Ag/AgCl
₂
Entry
Cobalt porphyrin
CoII
CoIII
1
2
3
4
5
6
CoII(tpfpp)
CoII(tmcpp)
CoII(tdcpp)
CoII(tpp)
0.475
0.380
0.355
0.325
0.295
0.265
CoII(tmpp)
CoII(ttmpp)
a Conditions: cobaltII porphyrin (1 mmol dmϪ3), electrode Pt–Pt,
Et4NClO4 (0.1 mol dmϪ3) in DMF under Ar.
Table 2 Effect of substituted silanes on the hydroperoxygenation of
ethyl (2E,4E)-hexa-2,4-dienoate
CO2Et
OOH
CoII(tdcpp)(0.001 equiv.)
O2 (1 atm)
2
+
Substituted silane (1.2 equiv.)
CO2Et
CO2Et
CO2Et
1
PriOH - DCM (1:1)
28 °C, 40 min
OH
O
3
Fig. 1 Time course of the reaction of ethyl (2E,4E)-hexa-2,4-dienoate
1 (1 mmol) with 1 atm of oxygen and Et3SiH (1.1 mmol) catalyzed by
cobalt() porphyrins (0.0001 mmol) at 28 ЊC in PriOH–DCM (5 cm3,
1:1): (a) consumption of 1 and (b) production of 3. (᭿) [CoII(tpfpp)],
(ᮀ) [CoII(tmcpp)], (᭹) [CoII(tdcpp)], (᭺) [CoII(tpp)], (᭡) [CoII(tmpp)]
and (᭝) [CoII(ttmpp)]. Abbreviations: tpfpp = 5,10,15,20-tetrakis-
(pentafluorophenyl)porphine; tmcpp = 5,10,15,20-tetrakis(4-methoxy-
+
4
carbonylphenyl)porphine;
tdcpp = 5,10,15,20-tetrakis(2,6-dichloro-
Isolated yield (%)
phenyl)porphine; tpp = 5,10,15,20-tetraphenylporphine; tpm = 5,10,-
15,20-tetramesitylporphine;
methoxyphenyl)porphine.
ttmpp = [5,10,15,20-tetrakis(3,4,5-tri-
Entry
Substituted silane
2
3
4
1
2
3
4
5
6
7
Et3SiH
77
56
69
65
0
0
0
0
35
Trace
22
7
20
22
Me2(EtO)SiH
MePhSiH2
C6H13SiH3
PhSiH3
(EtO)3SiH
Ph3SiH
first examined. In propan-2-ol–DCM (1:1) as solvent, ethyl
(2E,4E)-hexa-2,4-dienoate 1 was allowed to react under 1 atm
of oxygen with 1.1 equiv. of triethylsilane at 28 ЊC in the pres-
ence of 0.0001 equiv. of metal complexes, and then the reaction
mixture was treated with trimethyl phosphite in order to con-
vert the intermediary hydroperoxide 2 into the corresponding
alcohol 3 (Scheme 2). The reaction’s progress was followed by
14
No reaction
No reaction
complexes used; the reaction of 1 was completed in 60 min in
the presence of 0.0001 equiv. of CoII(tdcpp). However, we
primarily used 0.001 equiv. of CoII(tdcpp) in subsequent
experiments, considering that the reaction is applied to various
substrates, which may include less reactive ones than 1.
Catalyst (0.0001 equiv.)
O
2 (1 atm)
CO2Et
Et3SiH (1.1 equiv.)
CO2Et
PriOH - DCM (1:1)
28 ˚C
OOH
The redox potential (E1/2) between CoII and CoIII was meas-
ured in DMF containing 0.1 mol dmϪ3 of Et4NClO4. The
cobalt porphyrins having redox potentials in the range from
0.27 to 0.38 V are reactive as catalysts, but CoII(tpfpp), having a
potential >0.45 V is not (Table 1). The consumption of the
substrate in the reaction decreases remarkably with decreasing
the redox potentials of the catalysts. It is assumed that active
oxygen species, produced during the reaction, easily decompose
the porphyrin ring of the catalysts owing to their high electron
density and/or their low steric hindrance; a similar relationship
between the catalytic activity and the redox potentials of
bis(1,3-diketonato)cobalt() complexes was reported for the
oxidation–reduction–hydration of olefins with oxygen and
propan-2-ol as a reductant.18
1
2
(MeO)3P (1.3 equiv.)
CO2Et
OH
3
Scheme 2
measurement of the consumption of 1 and the production of 3
by gas chromatography (Fig. 1). Under these reaction con-
ditions, neither bis(acetylacetonato)cobalt() [CoII(acac)2] nor
(N,NЈ-disalicylideneethylenediaminato)cobalt() [CoII(salen)]
had catalytic activity, although they were reported to catalyze
the peroxygenation of alkenes with oxygen and triethyl-
silane8 or the hydroxylation of alkenes with oxygen and
NaBH4.17 FeIII, MnIII and NiII complexes of 5,10,15,20-
tetrakis(2,6-dichlorophenyl)porphine [FeIII(tdcpp)Cl, MnIII-
(tdcpp)Cl and NiII(tdcpp)] did not act as catalysts. As shown in
Fig. 1, the reaction proceeded in the presence of all cobalt()
porphyrins except for CoII(tpfpp). CoII(tdcpp) was the most
suitable catalyst for the hydroperoxygenation among the metal
Second, the effect of substituted silanes on the hydroperoxy-
genation was examined and the results are depicted in Table 2.
The hydroperoxygenation of 1 using triethylsilane, ethoxy-
dimethylsilane, methylphenylsilane and n-hexylsilane pro-
ceeded smoothly to give the hydroperoxide 2 as a major product
along with ketone 4: since the ketone 4 was formed from the
hydroperoxide 2 by cobalt porphyrin-mediated degradation via
a redox cycle, the reaction mixture had to be post-treated and
3990
J. Chem. Soc., Perkin Trans. 1, 1998, 3989–3998

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Table 3 The hydroperoxygenation of conjugated dienesa
Entry Substrate
t/h
Product
Yield (%)b
OOH
CO2Et
1
2
0.67
1
77
68
CO2Et
OOH
n-Pr
CO2Et
n-Pr
CO2Et
OOH
CO2Et
CO2Et
3
1
70
CO2Et
Et
Et
Et
Et
HOO
HOO
4
5
2
2
74
90
CO2Et
CONH-c-C6H11
CO2Me
CONH-c-C6H11
OOH
MeO2C
6c
7
3
65
49
MeO2C
OOH
CO2Me
1.5
CHO
CHO
CHO
OOH
n-Bu
8
1.5
54
n-Bu
CHO
OOH
n-Hex
9
1
1
55
61
CO-t-Bu
O
n-Hex
n-Pr
CO-t-Bu
O
10
n-Pr
OOH
O
O
11
12
0.5
67
HOO
NO2
NO2
1
50
92
HOO
HOO
13
14
1
2
Unseparable mixture
Ph
a Conditions: substrate (1 mmol), [CoII(tdcpp)] (0.001 equiv.), O2 (1 atm), Et3SiH (1.1 equiv.), PriOH–DCM (5 cm3, 1:1) at 28 ЊC. b Isolated yield.
c 0.005 equiv. of CoII(tdcpp) was used.
separated by flash column chromatography as rapidly as pos-
sible after the completion of the reaction. On the other hand,
overreduction of 2 into the alcohol 3 was observed for phenyl-
silane. When triethoxysilane and triphenylsilane were used, no
reaction took place due to their weak reducibility. Triethylsilane
was found to be the most effective reductant among the silanes
used for the formation of the hydroperoxide 2.
required in order to accelerate the reaction. In addition, the
reaction of 1-nitrocycloocta-1,3-diene was found to afford
3-hydroperoxy-1-nitrocyclooct-2-ene. It is interesting to point
out that the present reaction conditions are mild enough to
permit the presence of reduction- and/or oxidation-labile
groups such as aldehyde, ketone and nitro groups on the
substrates. It is particularly noteworthy that 4-hydroperoxyalk-
2-enals such as (E)-4-hydroperoxyhex-2-enal and (E)-4-
hydroperoxynon-2-enal, remarkably cytotoxic and genotoxic
compounds produced during lipid peroxidation in biological
systems,19 can be synthesized in one step from commercially
available (2E,4E)-alka-2,4-dienals.‡ On the other hand, the
reaction of cycloocta-1,3-diene gave the allyl hydroperoxide in
high yield (entry 13), while that of 6-phenylhexa-1,3-diene
resulted in an inseparable mixture of regioisomeric hydroperox-
ides (entry 14). These results suggest that the substitution of
the electron-withdrawing group on the diene is important
for regioselective hydroperoxygenation. To the best of our
Reactivity and selectivity in the hydroperoxygenation
The procedure of the hydroperoxygenation using both 0.001
equiv. CoII(tdcpp) as the catalyst and 1.1 equiv. of triethylsilane
as the reductant was applied to conjugated dienes (Table 3). The
hydroperoxygenation of dienes conjugated with electron-
withdrawing groups predominantly gave the corresponding
γ-hydroperoxy-α,β-unsaturated compounds along with a small
amount of γ-oxo-α,β-unsaturated compounds, as shown in
entries 1–12. No other isomer hydroperoxygenated at a different
position was observed in all cases. From alkadienoic esters,
alkadienamide, alkadienals and alkadienones, the correspond-
ing γ-hydroperoxy compounds were produced in good or
moderate yields, independent of the alkyl substituents in the
substrates. For entry 6, an increased amount of CoII(tdcpp) was
‡ (2E,4E)-2,4-alkadienals: (2E,4E)-2,4-Hexadienal and (2E,4E)-2,4-
nonadienal were purchased from Tokyo Kasei Kogyo Co., Ltd. and
freshly distilled under reduced pressure.
J. Chem. Soc., Perkin Trans. 1, 1998, 3989–3998
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Table 4 The hydroperoxygenation of acrylic estersa
Entry
Substrate
t/h
Product
Yield (%)b
OOH
COO
1
4
72
COO
HOO
HOO
2
3
2
80
78
COO
COO
C4H9
C4H9
0.5
CO2Et
CO2Et
CO2C4H9
CO2C4H9
HOO
HOO
4
5
6
1
81
89
86
CO2C4H9
COO
CO2C4H9
COO
2
HOO
CO2
CO2
CO2
CO2
1.5
a Conditions: substrate (1 mmol), [CoII(tdcpp)] (0.001 equiv.), O2 (1 atm), Et3SiH (1.1 equiv.), PriOH–DCM (5 cm3, 1:1) at 28 ЊC. b Isolated yield.
knowledge, the present method is the first to enable direct
synthesis of γ-hydroperoxy-α,β-unsaturated carbonyl and nitro
compounds.
enoic esters into the corresponding peroxides.8 On the contrary,
no reaction using our hydroperoxygenation conditions was
observed for non-conjugated olefins. On the basis of these dif-
ferences, Mukaiyama’s method and our method are considered
to be complementary to each other for the direct preparation of
(hydro)peroxy compounds from olefins.
Acrylic ester derivatives were found to be converted into
α-hydroperoxy compounds (Table 4). We previously found that
non-conjugated olefins such as dodec-1-ene and 3-(4-methoxy-
phenyl)prop-1-ene were unreactive and alk-2-enoic esters
less reactive under similar reaction conditions.12 According
to the different reactivities for olefins on the reaction, the
chemoselective hydroperoxygenation of the acrylic moiety
became feasible, as shown in entries 5 and 6.
Mechanism
Two types of mechanism of cobalt() complex-catalyzed
reduction–oxygenation of olefins have been proposed previ-
ously. Okamoto et al. reported that the reaction of styrene with
oxygen and NaBH4 proceeded via the σ-alkylcobalt (Scheme
3).17 On the other hand, Drago et al. proposed that cobalt()
It has already been described by us that styrene derivatives
were directly converted into acetophenone derivatives in many
cases when 0.001 equiv. of CoII(tdcpp) was used as the
catalyst.12 Since rapid degradation of the corresponding
hydroperoxides mediated by CoII(tdcpp) was the reason for
producing the acetophenones as the major product, a decrease
in the amount of CoII(tdcpp) was attempted for the preparation
of the hydroperoxides as the major product (Table 5). When
0.0001 equiv. of CoII(tdcpp) was used in the reaction of styrene,
the yield of α-phenethyl hydroperoxide increased dramatically
(entries 1 and 2). Under similar conditions to those shown in
entry 2, the reaction of the other styrene derivatives also gave
the corresponding hydroperoxides in good yields (entries 3–7).
-
BH4
RCH=CH2
RCH(CH3)-CoIIIL
CoIIL
O2
HCoIL
-
BH4
RCH(CH3)-OOCoIIIL
RCH(CH3)-OH + HCoIL
Scheme 3
hydroperoxide produced with oxygen from a cobalt() Schiff-
base complex was the reactive intermediate in the reaction of
olefins (Scheme 4).21 To study the mechanism of the present
hydroperoxygenation, we performed the following experiments.
1
All hydroperoxides were identified by H NMR, 13C NMR,
IR and MS analysis, although not by elemental analysis
because of their lability. The hydroperoxide content of the
products was analyzed by iodometric titration,20 and their per-
oxide values were over 96% in all cases.
RCH=CH2
R'CH2OH
O2
RCH(CH3)-OOH + CoIIL
CoIIL
HOOCoIIIL
R'CH2OH
Thus, our hydroperoxygenation of conjugated olefins was
observed to take place rapidly, chemoselectively and regio-
selectively. Mukaiyama et al. reported that the peroxy-
genation reaction of non-conjugated olefins proceeded over 5 h
with CoII(acac)2 as the catalyst, however, the combined use of
CoII(acac)2 and tert-butyl hydroperoxide or the use of the other
cobalt complexes such as CoII(modh)§ instead of CoII(acac)2
was necessary for the smooth conversion of styrenes and alk-2-
RCH(CH3)-OH + RCOCH3 + CoIIL
Scheme 4
Deuterium incorporation during the course of the hydro-
peroxygenation of ethyl (2E,4E)-5-methylhexa-2,4-dienoate
was examined by use of triethyldeuterosilane instead of tri-
ethylsilane in propan-2-ol or [O-2H]propan-2-ol. After the
hydroperoxides had been reduced with trimethyl phosphite, the
distribution of deuterium in the corresponding alcohols was
§ CoII(modh): bis(1-morpholino-5,5Ј-dimethyl-1,2,4-hexanetrionato)-
cobalt().
1
determined on the basis of their H NMR spectra (Table 6).
3992
J. Chem. Soc., Perkin Trans. 1, 1998, 3989–3998

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Table 5 The hydroperoxygenation of styrene derivativesa
CoII(tdcpp)
O2 (1 atm)
OOH
O
Et3SiH (1.1 equiv.)
Substrate
+
PriOH - DCM (1:1)
28 ˚C
R
R
Yield (%)b
CoII(tdcpp)/
equiv.
Hydro-
peroxide
Entry Substrate
t/h
3
Ketone
76
1
2
3
R = H
R = H
0.001
13
80
0.0001
1
trace
R = OMe
R = Me
R = Cl
0.0001
0.0001
0.0001
1
72
87
78
22
R
4
0.5
2
trace
19
5
-
0.0001
1
72
6
0.0001
trace
7
1.5
60
a Conditions: substrate (1 mmol), [CoII(tdcpp)] (0.0001 equiv. or 0.001 equiv.), O2 (1 atm), Et3SiH (1.1 equiv.), PriOH–DCM (5 cm3, 1:1) at 28 ЊC.
b Isolated yield.
Table 6 Deuterium distribution in the product on the hydroperoxy-
genation of ethyl (2E,4E)-5-methylhexa-2,4-dienoate
exchange between triethyldeuterosilane and a large excess of
propan-2-ol occurs under the reaction conditions. These results
suggest that the origin of hydrogen in the product is from
triethylsilane rather than propan-2-ol.
CO2Et
Evidence for the coordination and activation of the con-
jugated olefins by CoII(tdcpp) was sought using EPR spectro-
scopy. The EPR spectral data for CoII(tdcpp) in the absence and
in the presence of olefins at 77 K in vacuo are collected in Table
7. CoII(tdcpp) showed a typical four-coordinated spectrum in
DCM, similar to that of CoII(tpp) reported in the literature.22 In
DCM, the spectrum of CoII(tdcpp) in the presence of 1, one of
the reactive substrates on the hydroperoxygenation, indicated
the formation of a five-coordinated complex (g⊥ = 2.292,
g|| = 2.033), whereas that in the presence of dec-1-ene, the
unreactive substrate, was entirely unchanged. Moreover, in the
presence of 1, CoII(tdcpp) showed the same five-coordinated
spectrum in propan-2-ol–DCM (1:1) as in DCM. On the other
hand, we observed a different type of five-coordinate spectrum
(g⊥ = 2.387, g|| = 2.029) in the absence of 1 in propan-2-ol–
DCM, which probably resulted from the coordination of
propan-2-ol to CoII(tdcpp). It is considered that the coordin-
ation of conjugated olefins to CoII(tdcpp) contributes to the
activation and regioselectivity of the hydroperoxygenation of
the olefins.
COII(tdcpp)(0.001 equiv.)
Alcohol - DCM
28 °C, 2 h
O2 (1 atm)
Reductant (1.1 equiv.)
(MeO)3P (1.2 equiv.)
1 h
OH
CO2Et
H or D
Deuterium
Entry
Reductant
Alcohol
Yield (%)a
distribution (%)b
1
2
3
4
Et3SiH
Et3SiH
Et3SiD
Et3SiD
PriOH
PriOD
PriOH
PriOD
81
78
74
74
0
0
From these results, we deduced the reaction mechanism for
the hydroperoxygenation as shown in Scheme 5. The olefin acti-
vated by cobalt() porphyrin is reduced by triethylsilane to
form σ-alkylcobalt complex A as a reactive intermediate, which
subsequently reacts with oxygen to produce alkylperoxycobalt
complex B. Finally, the hydroperoxide is produced from the
complex B, and cobalt() porphyrin is regenerated along with
triethylsilyl isopropoxide.
66
100
a Isolated yield. b Analyzed by 1H NMR spectroscopy.
When triethyldeuterosilane was used in [O-2H]propan-2-ol for
the reaction, complete incorporation of deuterium occurred at
the δ-position of the product (entry 4). No deuterium incorpor-
ation was observed for the combined used of triethylsilane and
[O-2H]propan-2-ol (entry 2). On the other hand, partial deuter-
ium incorporation (66%) was observed for the combined use of
triethyldeuterosilane and propan-2-ol. It is presumed that D–H
Conclusion
A wide variety of hydroperoxides was prepared using the
present hydroperoxygenation of conjugated olefins in good or
J. Chem. Soc., Perkin Trans. 1, 1998, 3989–3998
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Table 7 EPR parameters of CoII(tdcpp) under various conditionsa
Entry
Solvent
DCM
Olefin
g⊥
g||
Coordination No.
none
1
2
2.723
2.292
2.042
2.033
4
5
DCM
CO2Et
CO2Et
DCM
3
4
2.723
2.387
2.042
2.029
4
5
PriOH - DCM
none
PriOH - DCM
5
2.292
2.033
5
a EPR spectra were measured at 77 K in vacuo in solvent with 0.0005 mol dmϪ3 of CoII(tdcpp) and 0.5 mol dmϪ3 of olefin.
Et3SiOPri
CO2Et
CoIIL
Et3Si
CoIIIL
CoIIL
O
OOH
CO2Et
Et3SiH
CO2Et
OH
Et3Si
CoIIIL
O
CoIIIL
CO2Et
O
A
CO2Et
B
O2
Scheme 5
moderate yields. The following characteristic features are
noted. (i) Conditions: the reaction proceeds rapidly under
neutral and mild conditions (at room temperature under 1
atm of O2). (ii) Reactivity: the reaction of α,β,γ,δ-unsaturated
carbonyl compounds, acrylic esters, α-substituted acrylic
esters and styrene derivatives proceeds completely, while that
of non-conjugated olefins does not. (iii) Selectivity: α,β,γ,δ-
unsaturated carbonyl compounds are predominantly converted
to γ-hydroperoxy-α,β-unsaturated carbonyl compounds, and
acrylic esters, α-substituted acrylic esters and styrene derivatives
to α-hydroperoxygenated compounds.
and in the presence of ethyl (2E,4E)-hexa-2,4-dienoate or dec-
1-ene. The g factors of the spectra were determined by com-
parison with those of a MnII marker. Cyclic voltammograms of
0.001 mol dmϪ3 cobalt() porphyrins were recorded on a BAS
Model CV-27 in DMF solution containing 0.1 mol dmϪ1 tetra-
ethylammonium perchlorate (Tokyo Kasei Kogyo Co., Ltd.)
under Ar. Both the working and auxiliary electrodes were
platinum and the reference electrode was Ag/AgCl. GC was
performed on a Shimadzu GC-8A chromatograph instrument
with SE-30-supporting glass column (200 mm × 3.2 mm) and
a flame ionization detector (FID). The consumption of the
substrate and the yield of the product were calculated from
peak areas on a Shimadzu chromatopack C-R3A. N2 was used
as the carrier gas (1.1 kg cmϪ3). The temperature program used
was 1 ЊC minϪ1 from 70 to 270 ЊC. The injection port and FID
were kept at 270 ЊC. Silica gel BW-300 purchased from Fuji
Silysia Co., Ltd. was used for flash column chromatography.
Propan-2-ol and DCM were distilled from calcium hydride.
DMF was distilled under reduced pressure from calcium
hydride. Substituted silanes and chlorotriethylsilane were
purchased from Shin-Etsu Chemical Co. Ltd. and [O-2H]-
propan-2-ol and lithium aluminium deuteride from Aldrich
Chemical Co., Inc. 5,10,15,20-Tetrakis(pentafluorophenyl)por-
phine (tpfpp), 5,10,15,20-tetrakis(4-methoxycarbonylphenyl)-
porphine (tmcpp), 5,10,15,20-tetrakis(2,6-dichlorophenyl)por-
phine (tdcpp), 5,10,15,20-tetraphenylporphine (tpp), 5,10,15,20-
tetramesitylphenylporphine (tmp) and 5,10,15,20-tetrakis-
(3,4,5-trimethoxyphenyl)porphine (ttmpp) were prepared
Experimental
General
1H and 13C NMR spectra were recorded on a Bruker AC-250P
spectrometer in CDCl3 solution with TMS (δ 0.00) as an
internal standard. IR spectra were measured in CHCl3 solution
on a Hitachi IR 270-30 spectrometer. High resolution mass
spectrometry (HRMS) was performed on a Hitachi M-
2000AM mass spectrometer in electron impact mode at 70 eV,
and low resolution mass spectrometry in secondary ionization
(SIMS) using 3-nitrobenzyl alcohol as a matrix. EPR spectra
were recorded at 77 K on a JEOL RE-1X EPR spectrometer.
The solution of CoII(tdcpp) in DCM or in propan-2-ol–DCM
(1:1) was prepared by the complete removal of dissolved oxy-
gen according to the usual freeze–thaw method. The EPR spec-
trum of the CoII(tdcpp) solution was measured in the absence
3994
J. Chem. Soc., Perkin Trans. 1, 1998, 3989–3998

View Article Online
according to the literature methods.23,24 The insertion of
cobalt() ion into the porphyrins by Alder’s method25 gave the
corresponding cobalt() porphyrins. Triethyldeuterosilane was
prepared by the reaction of chlorotriethylsilane with lithium
aluminium deuteride by the same method as described in the
literature.26
1180, 1040 and 980; δH(250 MHz, CDCl3) 0.90 (3 H, t, J 7.2 Hz,
CH3), 1.30 (3 H, t, J 7.2 Hz, OCH2CH3), 1.30–1.68 (6 H, m,
3 × CH2), 4.19 (2 H, q, J 7.3 Hz, OCH2), 4.52 (1 H, dd, J 6.7
and 6.8 Hz, CHOOH), 6.04 (1 H, d, J 16.0 Hz, CH᎐CHCO),
᎐
6.90 (1 H, dd, J 6.8 and 16.0 Hz, CH᎐CHCO) and 8.84 (1 H, s,
᎐
OOH); δC(63 MHz, CDCl3) 13.87, 14.19, 22.56, 27.23, 31.84,
60.79, 84.64 (COOH), 123.14, 146.88 and 166.53; m/z (HRMS)
203.1280 (MHϩ; C10H19O4 requires MH, 203.1283).
Time course of the reaction of ethyl (2E,4E)-hexa-2,4-dienoate 1
To a mixture of 1 (140 mg, 1 mmol) and a catalyst (0.095 mg,
0.0001 mmol) in 5 cm3 of propan-2-ol and DCM (1:1) in a 50
cm3 kjeldahl flask with a three-way stopcock was added
4-bromotoluene (85 mg, 0.5 mmol) as an internal standard for
GC. The atmosphere in the flask was replaced with oxygen by
bubbling for 5 min and then an oxygen balloon was attached to
the flask through the three-way stopcock. Triethylsilane (0.18
cm3, 1.1 mmol) was added to the solution at 28 ЊC and the
reaction mixture was stirred. 0.1 cm3 of the solution was with-
drawn at appropriate intervals, followed by immediate treat-
ment with 0.01 cm3 of trimethyl phosphite. The consumption
of 1 and the production of the alcohol 3 were measured by GC.
Ethyl (E)-4-hydroperoxy-5-methylhex-2-enoate
Rf (Hexane–EtOAc 4:1) 0.23; νmax(CHCl3)/cmϪ1 3580, 3440,
3070, 3000, 2980, 2950, 2910, 1730, 1680, 1480, 1460, 1420,
1390, 1350, 1320, 1300, 1260, 1200, 1150, 1140, 1120, 1060 and
1000; δH(250 MHz, CDCl3) 0.90 (3 H, d, J 6.9 Hz, CH3), 0.98
(3 H, d, J 6.8 Hz, CH3), 1.31 (3 H, t, J 7.2 Hz, OCH2CH3), 1.82–
2.00 (1 H, m), 4.13–4.31 (3 H, m, OCH2 and CHOOH), 6.06
(1 H, d, J 15.7 Hz, CH᎐CHCO), 6.90 (1 H, dd, J 7.3 and 15.7
᎐
Hz, CH᎐CHCO) and 9.14 (1 H, br s, OOH); δ (63 MHz,
᎐
C
CDCl3) 14.08, 18.02, 18.37, 30.69, 60.71, 89.43 (COOH),
124.02, 145.42 and 166.41; m/z (HRMS) 189.116 (MHϩ;
C9H17O4 requires MH, 189.1127).
Typical procedure for synthesis of ethyl (E)-4-hydroperoxyhex-2-
enoate 2
Ethyl (E)-4-hydroperoxyhex-2-enoate
The dienoate 1 (140 mg, 1 mmol) and CoII(tdcpp) (0.95 mg,
0.001 mmol) were dissolved in 5 cm3 of propan-2-ol–DCM
(1:1) in a 50 cm3 kjeldahl flask equipped with three-way stop-
cock. The atmosphere in the flask was replaced with oxygen by
bubbling for 5 min, and then an oxygen balloon was attached to
the flask through the three-way stopcock. After triethylsilane
(0.18 cm3, 1.1 mmol) had been added to the solution at 28 ЊC,
the reaction was checked by TLC until the substrate was com-
pletely consumed. The solvent was removed under reduced
pressure, and the residue was purified by flash column chrom-
atography on silica gel with n-hexane–ethyl acetate (20:1–10:1
v/v) to afford oily hydroperoxide 2 (133 mg, 77%).
Rf (Hexane–EtOAc 4:1) 0.30; νmax(CHCl3)/cmϪ1 3550, 3400,
3050, 3000, 2975, 2900, 1710, 1660, 1460, 1380, 1320, 1300,
1230, 1200, 1160, 1140, 1110, 1050 and 1000; δH(250 MHz,
CDCl3) 0.88 (6 H, t, J 7.5 Hz, 2 × CH3), 1.28 (3 H, t, J 7.1 Hz,
OCH2CH3), 1.71 (4 H, q, J 7.5 Hz, CH2), 4.21 (2 H, q, J 7.1 Hz,
OCH ), 5.95 (1 H, d, J 16.2 Hz, CH᎐CHCO), 6.89 (1 H, d,
᎐
2
J 16.2 Hz, CH᎐CHCO) and 8.23 (1 H, s, OOH); δ (63 MHz,
᎐
C
CDCl3) 7.48, 12.31, 26.70, 60.69, 86.67 (COOH), 121.57, 149.82
and 166.77; m/z (HRMS) 203.1320 (MHϩ; C10H19O4 requires
MH, 203.1283).
Cyclohexyl (E)-4-ethyl-4-hydroperoxyhex-2-enamide
Rf (Hexane–EtOAc 1:1) 0.35; mp 126.5–127.5 ЊC (decomp.);
νmax(CHCl3)/cmϪ1 3460, 3320, 3030, 2980, 2950, 2860, 1680,
1640, 1520, 1460, 1340, 1160, 1100 and 990; δH(250 MHz,
CDCl3) 0.86 (6 H, t, J 7.4 Hz, CH3), 1.08–2.41 (14 H, m,
7 × CH2), 3.80–3.83 (1 H, m, CH), 5.94 (1 H, d, J 15.8 Hz,
Deuterium incorporation on the reaction of (2E,4E)-5-methyl-
hexa-2,4-dienoate with triethyldeuterosilane
To a DCM solution (1 cm3) of ethyl (2E,4E)-5-methylhexa-2,4-
dienoate (77 mg, 0.5 mmol) and CoII(tdcpp) (0.47 mg, 0.0005
mmol) was added 1 cm3 of [O-2H]propan-2-ol. The atmosphere
in the flask was replaced with oxygen by bubbling for 5 min
and then an oxygen balloon was attached to the flask. Triethyl-
deuterosilane (0.09 cm3, 0.55 mmol) was added to the solution
and the mixture was stirred at 28 ЊC for 2 h, followed by treat-
ment with trimethyl phosphite (0.07 cm3, 0.6 mmol) at 0 ЊC
for 1 h at room temperature. After the solvent had been
removed under reduced pressure, the residue was purified by
silica gel column chromatography with n-hexane–ethyl acetate
(20:1–10:1 v/v) to afford oily ethyl (E)-4-hydroxy-5-methyl-
[5-2H1]hex-2-enoate (64 mg, 74%).
CH᎐CHCO), 6.01 (1 H, br s, NH), 6.74 (1 H, d, J 15.8 Hz,
᎐
CH᎐CHCO) and 9.43 (1 H, br s, OOH); δ (63 MHz, CDCl )
᎐
C
3
7.56, 24.84, 25.51, 26.66, 33.04, 48.41, 86.61 (COOH), 124.13,
145.43, 164.99 and 165.22; m/z (HRMS) 255.1812 (Mϩ;
C14H25O3 requires M, 255.1834).
Dimethyl (E)-4-hydroperoxyhex-2-ene-1,5-dioate
Rf (Hexane–EtOAc 4:1) 0.30; νmax(CHCl3)/cmϪ1 3550, 3400,
3050, 3020, 2980, 2950, 2900, 1740, 1680, 1460, 1430, 1410,
1390, 1320, 1230, 1210, 1150, 1110, 1070 and 1040; δH(250
MHz, CDCl3) 2.58–2.83 (2 H, m, CH2), 3.73 (3 H, s, CH3), 3.76
(3 H, s, CH3), 5.00 (1 H, m, CHOOH), 6.13 (1 H, d, J 15.9 Hz,
Ethyl (E)-4-hydroperoxyhex-2-enoate
CH᎐CHCO) and 6.93 (1 H, dd, J 6.1 and 15.9 Hz, CH᎐CHCO)
᎐
᎐
Rf (Hexane–EtOAc 4:1) 0.19; νmax(CHCl3)/cmϪ1 3550, 3400,
3050, 3000, 2975, 2900, 1720, 1670, 1470, 1375, 1320, 1300,
1260, 1200, 1140, 1110, 1040 and 990; δH(250 MHz, CDCl3)
0.95 (3 H, t, J 7.5 Hz, CH3), 1.30 (3 H, t, J 7.2 Hz, OCH2CH3),
1.56–1.70 (2 H, m, CH2), 4.22 (2 H, q, J 7.2 Hz, OCH2), 4.45
(1 H, dd, J 6.7 and 6.8 Hz, CHOOH), 6.04 (1 H, d, J 15.8 Hz,
and 9.67 (1 H, br s, OOH); δC(63 MHz, CDCl3) 37.18, 51.83,
51.96, 80.22 (COOH), 123.35, 144.33, 166.58 and 170.76; m/z
(SIMS) 205 (MHϩ).
(E)-4-Hydroperoxyhex-2-enal
Rf (Hexane–EtOAc 4:1) 0.12; νmax(CHCl3)/cmϪ1 3550, 3400,
3030, 2980, 2950, 2880, 2830, 1700, 1640, 1465, 1390, 1220,
1120, 1090 and 980; δH(250 MHz, CDCl3) 0.99 (3 H, t, J 7.5 Hz,
CH3), 1.59–1.78 (2 H, m, CH2), 4.60 (1 H, q, J 6.4 Hz,
CH᎐CHCO), 6.89 (1 H, dd, J 6.8 and 15.8 Hz, CH᎐CHCO)
᎐
᎐
and 9.34 (1 H, br s, OOH); δC(63 MHz, CDCl3) 9.33, 14.02,
25.13, 60.69, 85.55 (COOH), 122.99, 146.60 and 175.37; m/z
(HRMS) 175.0922 (MHϩ; C8H15O4 requires MH, 175.0970).
CHOOH), 6.31 (1 H, dd, J 7.8 and 16.0 Hz, CH᎐CHCHO),
᎐
6.83 (1 H, dd, J 6.4 and 16.0 Hz, CH᎐CHCHO), 8.90 (1 H, br s,
᎐
Ethyl (E)-4-hydroperoxyoct-2-enoate
Rf (Hexane–EtOAc 4:1) 0.25; νmax(CHCl3)/cmϪ1 3550, 3400,
OOH) and 9.78 (1 H, d, J 7.8 Hz, CHO); δC(63 MHz, CDCl3)
9.50, 25.23, 85.52 (COOH), 133.09, 155.45 and 193.91; m/z
(HRMS) 131.0702 (MHϩ; C6H11O3 requires MH, 131.0708).
3030, 2960, 2940, 2860, 1720, 1660, 1475, 1375, 1320, 1270,
J. Chem. Soc., Perkin Trans. 1, 1998, 3989–3998
3995

View Article Online
(E)-4-Hydroperoxynon-2-enal
130.48 and 131.29; m/z (HRMS) 142.1005 (Mϩ; C8H14O2
requires M, 142.0994).
Rf (Hexane–EtOAc 4:1) 0.15; νmax(CHCl3)/cmϪ1 3550, 3400,
3030, 2970, 2950, 2850, 1700, 1650, 1475, 1390, 1340, 1230,
1140, 1120 and 990; δH(250 MHz, CDCl3) 0.89 (3 H, t, J 6.5 Hz,
CH3), 1.21–1.73 (8 H, m, 4 × CH2), 4.66 (1 H, dd, J 6.3 and 6.5
Cyclohexyl 2-hydroperoxypropanoate
Rf (Hexane–EtOAc 4:1) 0.20; νmax(CHCl3)/cmϪ1 3450, 3050,
3000, 2950, 2860, 1730, 1460, 1390, 1360, 1340, 1290, 1220,
1160, 1120, 1090, 1040, 1010 and 995; δC(250 MHz, CDCl3)
1.39 (3 H, d, J 7.0 Hz, CH3), 1.45–1.84 (10 H, m, 5 × CH2), 4.60
(1 H, q, J 7.0 Hz, CHOOH), 4.88 (1 H, m, CH) and 9.70 (1 H, s,
OOH); δC(63 MHz, CDCl3) 15.34, 23.58, 25.23, 31.43, 74.02,
79.47 (COOH) and 172.42; m/z (HRMS) 189.1118 (MHϩ;
C9H17O4 requires MH, 189.1127).
Hz, CHOOH), 6.32 (1 H, dd, J 7.8 and 15.8 Hz, CH᎐CHCHO),
᎐
6.82 (1 H, dd, J 6.5 and 15.8 Hz, CHCHCHO), 8.51 (1 H, br s,
OOH) and 9.59 (1 H, d, J 7.8 Hz, CHO); δC(63 MHz, CDCl3)
15.79, 22.43, 24.79, 31.58, 32.02, 84.48 (COOH), 133.00, 155.51
and 193.72; m/z (HRMS) 173.1214 (MHϩ; C9H17O3 requires
MH, 173.1178).
(E)-6-Hydroperoxy-2,2-dimethyltridec-4-en-3-one
Cyclohexyl 2-hydroperoxy-2-methylpropanoate
Rf (Hexane–EtOAc 4:1) 0.34; νmax(CHCl3)/cmϪ1 3550, 3400,
3030, 2980, 2950, 2870, 1700, 1640, 1490, 1480, 1410, 1380,
1330, 1290, 1240, 1150, 1080, 1020 and 990; δH(250 MHz,
CDCl3) 0.88 (3 H, t, J 6.8 Hz, CH3), 1.17 (9 H, s, 3 × CH3),
1.26–1.66 (12 H, m, 6 × CH2), 4.53 (1 H, dt, J 6.3 and 6.5 Hz,
Rf (Hexane–EtOAc 4:1) 0.32; νmax(CHCl3)/cmϪ1 3470, 3030,
3000, 2950, 2860, 1720, 1470, 1450, 1390, 1360, 1290, 1220,
1160, 1120, 1040 and 1010; δH(250 MHz, CDCl3) 1.48 (6 H, s,
2 × CH3), 1.36–1.87 (10 H, m, 5 × CH2), 4.86 (1 H, m, CH) and
9.37 (1 H, br s, OOH); δC(63 MHz, CDCl3) 22.52, 23.37, 25.21,
27.05, 73.72, 83.42 (COOH) and 173.92; m/z (HRMS) 203.1263
(MHϩ; C10H19O4 requires MH, 203.1283).
CHOOH), 6.71 (1 H, d, J 15.6 Hz, CH᎐CHCO), 6.86 (1 H, dd,
᎐
J 6.5 and 15.6 Hz, CHCHCO) and 9.22 (1 H, br s, OOH); δC(63
MHz, CDCl3) 14.09, 22.63, 25.16, 26.04, 29.11, 29.44, 31.76,
32.23, 43.16, 85.07 (COOH), 125.57, 145.03 and 205.14; m/z
(HRMS) 257.2136 (MHϩ; C15H29O3 requires MH, 257.2117).
Ethyl 2-hydroperoxy-2-methylhexanoate
Rf (Hexane–EtOAc 4:1) 0.44; νmax(CHCl3)/cmϪ1 3500, 3050,
3000, 2975, 2900, 1740, 1490, 1480, 1390, 1360, 1330, 1290,
1260, 1230, 1150, 1100, 1080 and 1030; δH(250 MHz, CDCl3)
0.89 (3 H, t, J 7.0 Hz, CH3), 1.37 (3 H, t, J 7.1 Hz, OCH2CH3),
1.22–1.93 (6 H, m, 3 × CH2), 1.49 (3 H, s, CH3), 4.25 (2 H, q,
J 7.1 Hz, OCH2) and 9.22 (1 H, s, OOH); δC(63 MHz, CDCl3)
13.90, 14.22, 20.41, 22.83, 25.29, 36.00, 61.46, 86.13 (COOH)
and 174.49; m/z (HRMS) 191.1297 (MHϩ; C9H19O4 requires
MH, 191.1283).
2-(2Ј-Hydroperoxyhexylidene)cyclohexanone
Rf (Hexane–EtOAc 4:1) 0.12; νmax(CHCl3)/cmϪ1 3550, 3400,
3030, 2950, 2880, 1690, 1630, 1460, 1440, 1420, 1380, 1310,
1220, 1140, 1075 and 980; δH(250 MHz, CDCl3) 0.89 (3 H, t,
J 5.3 Hz, CH3), 1.31–1.92 (10 H, m, 5 × CH2), 2.41–2.76 (4 H,
m, 2 × CH2), 4.71 (1 H, dt, J 6.6 and 8.9 Hz, CHOOH),
6.45 (1 H, dt, J 2.0 and 8.9 Hz, CH᎐C) and 9.27 (1 H, br s,
᎐
OOH); δC(63 MHz, CDCl3) 13.91, 22.37, 22.66, 23.37, 23.66,
27.28, 27.44, 31.72, 40.46, 81.02 (COOH), 136.92, 139.41 and
212.29; m/z (HRMS) 213.1441 (MHϩ; C12H21O3 requires MH,
213.1491).
Dibutyl 2-hydroperoxy-2-methylbutane-1,3-dioate
Rf (Hexane–EtOAc 4:1) 0.28; νmax(CHCl3)/cmϪ1 3480, 3050,
2975, 2950, 2880, 1740, 1730, 1460, 1350, 1300, 1220, 1185,
1120, 1060, 1020, 1000 and 960; δH(250 MHz, CDCl3) 0.93
(3 H, t, J 7.3 Hz, CH3), 0.95 (3 H, t, J 7.3 Hz, CH3), 1.33–1.47
(4 H, m, 2 × OCH2CH2), 1.53 (3 H, s, CH3), 1.56–1.71 (4 H, m,
2 × OCH2CH2CH2), 2.79 and 3.02 (2 H, ABq, J 15 Hz,
CH2CO), 4.10 (2 H, t, J 6.7 Hz, OCH2), 4.22 (2 H, t, J 6.6 Hz,
OCH2) and 9.61 (1 H, s, OOH); δC(63 MHz, CDCl3) 13.68,
19.07, 21.43, 30.42, 30.47, 41.07, 65.00, 65.75, 83.66 (COOH),
169.93 and 172.28; m/z (HRMS) 277.1621 (MHϩ; C13H25O6
requires MH, 277.1651).
4-Hydroperoxy-2,6,6-trimethylcyclohept-2-enone
Rf (Hexane–EtOAc 4:1) 0.21; νmax(CHCl3)/cmϪ1 3550, 3400,
3025, 2975, 2940, 2880, 1720, 1670, 1470, 1450, 1380, 1340,
1320, 1220, 1155, 1100, 1080, 1020 and 1005; δH(250 MHz,
CDCl3) 1.04 (3 H, s, CH3), 1.15 (3 H, s, CH3), 1.40–1.63 (2 H,
m, CH2), 1.86 (3 H, s, CH3), 2.34 and 2.53 (2 H, ABq, J 12.0 Hz,
CH ), 4.70–4.75 (1 H, m, CHOOH), 6.82 (1 H, br s, CH᎐C) and
᎐
2
8.69 (1 H, br s, OOH); δC(63 MHz, CDCl3) 18.84, 29.72, 29.89,
45.66, 56.09, 80.93 (COOH), 138.04, 144.64 and 201.81; m/z
(HRMS) 185.1159 (MHϩ; C10H17O3 requires MH, 185.1178).
Cyclohex-2-en-1-yl 2-hydroperoxypropanoate
3-Hydroperoxy-1-nitrocycloct-1-ene
Rf (Hexane–EtOAc 4:1) 0.25; νmax(CHCl3)/cmϪ1 3470, 3040,
2990, 2950, 2840, 1720, 1650, 1600, 1470, 1450, 1440, 1380,
1360, 1340, 1280, 1220, 1150, 1040, 1010 and 1000; δH(250
MHz, CDCl3) 1.48 (3 H, s, CH3), 1.49 (3 H, s, CH3), 1.54–2.08
(6 H, m, 3 × CH2), 5.33 (1 H, m, CH), 5.71 (1 H, dt, J 1.6
Rf (Hexane–EtOAc 4:1) 0.17; νmax(CHCl3)/cmϪ1 3550, 3450,
3030, 2950, 1700, 1600, 1520, 1450, 1340, 1280, 1220, 1040
and 960; δH(250 MHz, CDCl3) 1.49–1.79 (6 H, m, 3 × CH2),
1.95–2.07 (2 H, m, CH2), 2.44 [1 H, ddd, J 5.5, 11.7 and 14.9,
CH᎐C(NO )C(H)H], 3.05 [1 H, ddd, J 3.9, 4.0 and 14.9 Hz,
and 10.2 Hz, CH᎐CH), 6.00 (1 H, dt, J 3.3 and 10.2 Hz,
᎐
2
᎐
CH᎐C(NO )-C(H)H], 4.87 (1 H, m), 7.34 (1 H, d, J 7.1 Hz) and
CH᎐CH) and 9.19 (1 H, br s, OOH); δ (63 MHz, CDCl ) 18.67,
᎐
2
᎐
C
3
8.72 (1 H, br s, OOH); δC(63 MHz, CDCl3) 23.26, 25.35, 25.63,
27.94, 33.19, 82.95 (COOH), 137.26 and 150.47; m/z (SIMS)
205 (MHϩ).
22.56, 24.80, 28.12, 69.32, 83.57 (COOH), 124.81, 133.51 and
174.21; m/z (HRMS) 201.1141 (MHϩ; C10H17O4 requires MH,
201.1127).
3-Hydroperoxycyclooct-1-ene
2-[(E)-Hex-2-enoyloxy]ethyl 2-hydroperoxy-2-methylpropan-
oate
Rf (Hexane–EtOAc 4:1) 0.14; νmax(CHCl3)/cmϪ1 3680, 3550,
3400, 3020, 2950, 2880, 1660, 1600, 1460, 1410, 1330, 1220,
1100, 1070, 1030 and 960; δH(250 MHz, CDCl3) 1.07–1.69 (6 H,
m, 3 × CH2), 1.91–1.96 (2 H, m, CH2), 2.11–2.18 (2 H, m, CH2),
Rf (Hexane–EtOAc 4:1) 0.18; νmax(CHCl3)/cmϪ1 3450, 3050,
3000, 2970, 2900, 1750, 1740, 1670, 1480, 1470, 1460, 1400,
1380, 1360, 1340, 1300, 1230, 1200, 1170, 1140, 1080 and 1000;
δH(250 MHz, CDCl3) 0.94 (3 H, t, J 7.3 Hz, CH3), 1.38–1.59
(2 H, m, CH2CH3), 1.48 (6 H, s, 2 × CH3), 2.20 (2 H, dt, J 7.0
4.90–4.99 (1 H, m, CHOOH), 5.58–5.65 (1 H, m, CH᎐CH),
᎐
5.70–5.80 (1 H, m, CH᎐CH) and 8.30 (1 H, br s, OOH); δ (63
᎐
C
MHz, CDCl3) 23.38, 26.10, 26.38, 28.76, 32.75, 83.27 (COOH),
and 7.1 Hz, CH᎐CHCH ), 4.42 (4 H, br s, 2 × OCH ), 5.83
᎐
2 2
3996
J. Chem. Soc., Perkin Trans. 1, 1998, 3989–3998

View Article Online
(1 H, d, J 15.6 Hz, CH᎐CHCO), 7.01 (1 H, dt, J 7.0 and 15.6
Ethyl (E)-4-hydroxy-5-methylhex-2-enoate
᎐
Hz, CH᎐CHCO) and 9.35 (1 H, s, OOH); δ (63 MHz, CDCl )
᎐
Rf (Hexane–EtOAc 4:1) 0.18; νmax(CHCl3)/cmϪ1 3650, 3550,
3050, 3000, 2980, 2950, 2900, 1720, 1670, 1480, 1460, 1410,
1380, 1320, 1300, 1230, 1200, 1100, 1040 and 1000; δH(250
MHz, CDCl3) 0.95 (6 H, d, J 7.0 Hz, CH3), 1.29 (3 H, t, J 7.2
Hz, OCH2CH3), 1.77–1.90 (1 H, m), 2.37 (1 H, br s, OH), 4.09
(1 H, dd, J 4.8 and 7.2 Hz, CHOOH), 4.20 (2 H, q, J 7.2 Hz,
OCH ), 6.04 (1 H, dd, J 1.7 and 15.7 Hz, CH᎐CHCO) and 6.96
C
3
13.65, 21.20, 22.57, 34.29, 61.70, 63.20, 83.75 (COOH), 120.50,
150.95, 166.64 and 174.01; m/z (HRMS) 261.1297 (MHϩ;
C12H21O6 requires MH, 261.1338).
á-Methylbenzyl hydroperoxide
Rf (Hexane–EtOAc 10:1) 0.24; νmax(CHCl3)/cmϪ1 3675, 3550,
3100, 3075, 3040, 3000, 2960, 2950, 2920, 2900, 1600, 1500,
1460, 1380, 1360, 1330, 1300, 1280, 1220, 1130, 1080, 1040,
1020, 1000 and 995; δH(250 MHz, CDCl3) 1.37 (3 H, d, J 6.7
Hz, CH3), 5.09 (1 H, q, J 6.7 Hz, CHOOH), 7.31–7.41 (5 H, m,
ArH) and 7.72 (1 H, s, OOH); δC(63 MHz, CDCl3) 20.10, 83.60
(COOH), 126.50, 128.29 and 128.69; m/z (HRMS) 138.0724
(Mϩ; C8H10O2 requires M, 138.0681).
᎐
2
(1 H, dd, J 4.8 and 15.7 Hz, CH᎐CHCO); δ (63 MHz, CDCl )
᎐
C
3
14.18, 17.40, 18.19, 33.61, 60.41, 75.88 (COH), 121.09, 148.88
and 166.52; m/z (HRMS) 172.1071 (Mϩ; C9H16O3 requires M,
172.1099).
Ethyl (E)-4-hydroxy-5-methyl[5-2H1]hex-2-enoate
Rf (Hexane–EtOAc 4:1) 0.18; νmax(CHCl3)/cmϪ1 3650, 3550,
3050, 3000, 2980, 2950, 2900, 1720, 1670, 1480, 1460, 1410,
1380, 1320, 1300, 1230, 1200, 1100, 1030 and 950; δH(250 MHz,
CDCl3) 0.94 (6 H, s, CH3), 1.29 (3 H, t, J 7.2 Hz, OCH2CH3),
2.34 (1 H, br s, OH), 4.09 (1 H, d, J 4.8 Hz, CHOOH), 4.20
(2 H, q, J 7.2 Hz, OCH2), 6.04 (1 H, dd, J 1.6 and 15.7 Hz,
4-Methoxy-á-methylbenzyl hydroperoxide
Rf (Hexane–EtOAc 4:1) 0.20; νmax(CHCl3)/cmϪ1 3675, 3550,
3050, 3025, 2995, 2975, 2950, 2920, 2850, 1610, 1580, 1505,
1460, 1440, 1420, 1380, 1360, 1330, 1300, 1290, 1250, 1220,
1180, 1140, 1100, 1080, 1040 and 1000; δH(250 MHz, CDCl3)
1.44 (3 H, d, J 6.7 Hz, CH3), 3.78 (3 H, s, OCH3), 4.99 (1 H, q,
J 6.7 Hz, CHOOH), 6.87–6.90 (2 H, m, ArH), 7.24–7.30 (2 H,
m, ArH) and 8.43 (1 H, s, OOH); δC(63 MHz, CDCl3) 19.65,
55.16, 83.04 (COOH), 113.79, 129.94, 133.21 and 159.29; m/z
(HRMS) 168.0737 (Mϩ; C9H12O3 requires M, 168.0786).
CH᎐CHCO) and 6.95 (1 H, dd, J 4.8 and 15.7 Hz,
᎐
CH᎐CHCO); δ (63 MHz, CDCl ) 14.18, 17.27, 18.08, 32.85,
᎐
C
3
33.16, 33.47, 60.41, 75.84 (COH), 121.12, 148.83 and 166.49;
m/z (HRMS) 173.1152 (Mϩ; C9H15D1O3 requires M, 173.1161).
References
4,á-Dimethylbenzyl hydroperoxide
1 For a review see: W. Adam and A. J. Bloodworth, Annu. Rep. Prog.
Chem., Sect. B, Org. Chem., 1978, 75, 342.
Rf (Hexane–EtOAc 9:1) 0.13; νmax(CHCl3)/cmϪ1 3660, 3530,
3050, 3000, 2950, 1610, 1510, 1470, 1430, 1380, 1340, 1320,
1300, 1230, 1200, 1140, 1120, 1090, 1040 and 1020; δH(250
MHz, CDCl3) 1.44 (3 H, d, J 6.7 Hz, CH3), 2.35 (3 H, s,
ArCH3), 5.02 (1 H, q, J 6.7 Hz, CHOOH), 7.16–7.27 (4 H, m,
ArH) and 7.99 (1 H, s, OOH); δC(63 MHz, CDCl3) 19.70, 21.08,
83.49 (COOH), 126.53, 137.98 and 138.27; m/z (HRMS)
152.0845 (Mϩ; C9H12O2 requires M, 152.0837).
2 (a) H. A. J. Carless and R. J. Batten, J. Chem. Soc., Perkin Trans. 1,
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3 (a) A. G. Davies, R. V. Foster and A. M. White, J. Chem. Soc., 1953,
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4-Chloro-á-methylbenzyl hydroperoxide
Rf (Hexane–EtOAc 4:1) 0.23; νmax(CHCl3)/cmϪ1 3600, 3540,
3050, 3000, 2900, 1900, 1600, 1490, 1460, 1450, 1410, 1380,
1340, 1300, 1280, 1220, 1135, 1300, 1280, 1220, 1135, 1100,
1080, 1020 and 1000; δH(250 MHz, CDCl3) 1.41 (3 H, d, J 6.5
Hz, CH3), 4.99 (1 H, q, J 6.5 Hz, CHOOH), 7.24–7.34 (4 H, m,
ArH) and 8.54 (1 H, br s, OOH); δC(63 MHz, CDCl3) 19.88,
82.85 (COOH), 127.86, 128.62, 133.72 and 139.87; m/z
(HRMS) 172.0261 (Mϩ; C8H9ClO2 requires M, 172.0291).
4 (a) H. R. Williams and H. S. Mosher, J. Am. Chem. Soc., 1954, 76,
2984; (b) H. R. Williams and H. S. Mosher, J. Am. Chem. Soc., 1954,
76, 2987; (c) A. A. Frimer, J. Org. Chem., 1977, 42, 3194; (d)
P. Dussault and A. Sahli, J. Org. Chem., 1992, 57, 1009; (e) T. A.
Foglia and L. S. Silbert, J. Am. Oil Chem. Soc., 1992, 69, 151.
5 A. J. Bloodworth, C. J. Cooksey and D. Korkodilos, J. Chem. Soc.,
Chem. Commun., 1992, 926.
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(d) P. Dussault, A. Sahli and T. Westermeyer, J. Org. Chem., 1993,
58, 5469.
á,á-Dimethylbenzyl hydroperoxide
Rf (Hexane–EtOAc 9:1) 0.13; νmax(CHCl3)/cmϪ1 3550, 3100,
3075, 3020, 3000, 2950, 2870, 1610, 1500, 1460, 1380, 1370,
1330, 1270, 1220, 1160, 1105, 1080 and 1030; δH(250 MHz,
CDCl3) 1.60 (6 H, s, 2 × CH3) and 7.16–7.48 (6 H, m, ArH and
OOH); δC(63 MHz, CDCl3) 26.03, 83.91 (COOH), 125.30,
127.41, 128.49 and 144.45; m/z (HRMS) 152.0842 (Mϩ;
C9H12O2 requires M, 152.0837).
7 B. M. Choudary, N. Narender and V. Bhuma, Synlett, 1994, 641.
8 (a) S. Isayama and T. Mukaiyama, Chem. Lett., 1989, 573; (b)
S. Isayama and T. Mukaiyama, Chem. Lett., 1989, 1071; (c)
S. Isayama, Bull. Chem. Soc. Jpn., 1990, 63, 1305.
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2165.
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4497.
1-Hydroperoxyindene
Rf (Hexane–EtOAc 4:1) 0.20; νmax(CHCl3)/cmϪ1 3600, 3550,
3100, 3050, 2975, 2850, 1715, 1610, 1480, 1460, 1350, 1330,
1230, 1170, 1100, 1060, 1050 and 1035; δH(250 MHz, CDCl3)
2.23–2.31 (2 H, m, ArCH2CH2), 2.81 (1 H, dt, J 6.2 and 16.0
Hz, ArCH2), 3.07 (1 H, dt, J 8.0 and 16.0 Hz, ArCH2), 5.45
(1 H, t, J 4.7 Hz, CHOOH), 7.16–7.43 (3 H, m, ArH), 7.45 (1 H,
d, J 7.4 Hz, ArH) and 8.44 (1 H, br s, OOH); δC(63 MHz,
CDCl3) 29.93, 30.19, 89.14 (COOH), 123.85, 124.91, 125.96,
126.30, 139.69 and 145.40; m/z (HRMS) 150.0671 (Mϩ;
C9H10O2 requires M, 150.0681).
14 Y. Matsushita, K. Sugamoto, T. Nakama, T. Sakamoto and
T. Matsui, Tetrahedron Lett., 1995, 36, 1879.
15 K. Sugamoto, Y. Matsushita and T. Matsui, Lipids, 1997, 32, 903.
J. Chem. Soc., Perkin Trans. 1, 1998, 3989–3998
3997

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Paper 8/05888A
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J. Chem. Soc., Perkin Trans. 1, 1998, 3989–3998