1454
O. G. Kulinkovich et al.
SHORT PAPER
1H NMR: = 0.92 (t, 3H, J = 7.2 Hz), 1.42 (d, 3H, J = 5.0 Hz), 1.50–
1.72 (m, 2H), 2.24 (dt, 1H, J = 17.0, 7.0 Hz), 2.41 (dt, 1H, J = 17.0,
7.0 Hz), 3.13 (qd, 1H, J = 5.0, 2.0 Hz), 3.20 (d, 1H, J = 2.0 Hz).
the absence of signals corresponding to C=O carbon atom
in the 13C NMR spectra of compounds 2d–f indicated the
low relative contents of keto-forms 6d–f in the equilibri-
um mixture. Evidently, epoxy ketones 3 are formed from
peroxides 2 through intermediate hydroperoxyenolates 7.
Thus, isolated compounds 2d–f were transformed into ep-
oxy ketones 3d–f almost quantitatively under the action of
aqueous potassium hydroxide (TLC data).
(E)-2,3-Epoxydecan-4-one (3f)
Yield: 1.28 g (75%); colorless liquid; bp 72–73°C/2 Torr (Lit.19 bp
77–78°C/1.5 Torr).
IR (film): = 2931, 2859, 1712, 1460, 1421, 1376, 1235, 1173,
1141, 1044, 1006, 969, 848 cm–1.
1H NMR: = 0.88 (t, 3H, J = 6.3 Hz), 1.27 (m, 6H), 1.40 (d, 3H,
J = 5.0 Hz), 1.46–1.66 (m, 2H), 2.27 (dt, 1H, J = 17.2, 7.0 Hz), 2.45
(dt, 1H, J = 17.2, 7.0 Hz), 3.14 (qd, 1H, J = 5.0, 2.0 Hz), 3.17 (d, 1H,
J = 2.0 Hz).
In summary, we have presented a flexible and convenient
method for the preparation of aliphatic and arylaliphatic
, -epoxy ketones based on manganese-catalyzed oxida-
tion of easily available 1-substituted and 1,2-disubstituted
cyclopropanols followed by dehydration of the resulting
cyclic peroxides in the presence of potassium hydroxide.
Anal. Calcd for C10H18O2: C, 70.55; H, 10.66. Found: C, 70.94; H,
10.74.
1,2-Epoxydecan-3-one (3g)
The title compound was prepared according to General Procedure
except that 1.5 mol% Mn(II) abietate was used.
1H and 13C NMR spectra were recorded on a Bruker AC 200 (200
MHz) and Bruker AC 250 (62.5 MHz) spectrometer, respectively,
in CDCl3 using TMS as the internal standard. IR spectra were ob-
tained on a FT-IR Perkin Elmer 1000 spectrophotometer. Cyclopro-
panols 1a–g were synthesized following literature procedures (1a–
c,12 1d–g13).
Yield: 1.11 g (65%); colorless liquid; bp 86–89°C/3 Torr.
IR (film): = 2929, 2857, 1715, 1466, 1379, 1234, 1067, 947, 872,
724 cm–1.
1H NMR: = 0.88 (t, 3H, J = 7.0 Hz), 1.28 (m, 8H), 1.48–1.65 (m,
2H), 2.20–2.54 (m, 2H), 2.87 (dd, 1H, J = 6.0, 2.2 Hz), 2.99 (dd, 1H,
J = 6.0, 4.8 Hz), 3.42 (dd, 1H, J = 4.8, 2.2 Hz).
, -Epoxy Ketones 3a–g; General Procedure
A solution of corresponding cyclopropanol 1a–g (10 mmol) and
Mn(II) abietate (0.07 g, 1 mol%) in anhyd benzene (60 mL) was
stirred under an O2 atm at r.t. for 3–5 h (hazardous procedure). Then
aq KOH (0.5 M, 5 mL) was added and the mixture was vigorously
stirred at r.t. for 1–2 h. After filtration, the organic layer was sepa-
Anal. Calcd for C10H18O2: C, 70.55; H, 10.66. Found: C, 70.68; H,
10.63.
Isolation of 1,2-Dioxolan-3-ols 2d–f; General Procedure
A solution of the corresponding cyclopropanol 1d–f (10 mmol) and
Mn(II) abietate (0.07 g, 1 mol%) in anhyd benzene (60 mL) was
stirred under an O2 atm at r.t. for 3–5 h (hazardous procedure). The
solvent was removed under reduced pressure and peroxides 2d–f
were isolated by column chromatography on silica gel (EtOAc–cy-
clohexane, 1:1).
rated and the aqueous solution was extracted with benzene (3
5
mL). The combined organic phases were washed with sat. NH4Cl,
brine, and dried (Na2SO4). The solvent was removed and the crude
epoxides 3a–g were purified by distillation under reduced pressure
or by recrystallization.
(E)-3,4-Epoxydecan-2-one (3a)
Yield: 1.45 g (85%); bp 72–74°C/2 Torr (Lit.14 bp 84–85°C/1
Torr).
3,5-Diethyl-1,2-dioxolan-3-ol (2d)
Yield: 0.91 g (62%); colorless liquid (1:1 mixture of diastereo-
mers).
1H NMR: = 0.93 (t, 3H, J = 6.5 Hz), 1.20–1.54 (m, 8H), 1.55–1.71
(m, 2H), 2.06 (s, 3H), 3.08 (td, 1H, J = 5.0, 1.8 Hz), 3.17 (d, 1H,
J = 1.8 Hz).
IR (film): = 3444, 2970, 2882, 1713, 1463, 1381, 1282, 1212,
1159, 1011, 979, 905, 859 cm–1.
1H NMR: = 0.88–1.12 (m, 6H), 1.62–1.92 (m, 4H), 2.14–2.30 (m,
1H), 2.62–2.80 (m, 1H), 3.38 (br s, 1H), 4.16–4.32 (m, 0.5H), 4.34–
4.48 (m, 0.5H).
(E)-3,4-Epoxy-4-phenylbutan-2-one (3b)
Yield: 1.18 g (73%); mp 55–56°C (MeOH) [Lit.15 mp 54–55.5°C
(MeOH)].
1H NMR: = 2.19 (s, 3H), 3.48 (d, 1H, J = 1.8 Hz), 4.00 (d, 1H,
J = 1.8 Hz), 7.21–7.42 (m, 5H).
13C NMR: = 8.7, 9.0, 10.1, 10.3, 24.9, 27.4, 29.0, 29.4, 49.6, 49.8,
81.7, 83.3, 106.9, 107.8.
(E)-1,2-Epoxy-1-phenylpentan-3-one (3c)
Yield: 1.3 g (74%); mp 50–51°C (pentane) [Lit.16 mp 52–53°C (pe-
troleum ether)].
5-Methyl-3-propyl-1,2-dioxolan-3-ol (2e)
Yield: 1.17 g (80%); colorless liquid (1:1 mixture of diastereo-
mers).
1H NMR: = 1.11 (t, 3H, J = 7.0 Hz), 2.34–2.68 (m, 2H), 3.57 (d,
1H, J = 1.8 Hz), 3.97 (d, 1H, J = 1.8 Hz), 7.20–7.42 (m, 5H).
IR (film): = 3446, 2965, 2874, 1712 cm–1.
1H NMR: = 0.93 (t, 1.5H, J = 7.0 Hz), 0.94 (t, 1.5H, J = 7.0 Hz),
1.32 (d, 1.5H, J = 6.0 Hz), 1.36 (d, 1.5H, J = 6.0 Hz), 1.39–1.60 (m,
2H), 1.66–1.94 (m, 2H), 2.12–2.28 (m, 1H), 2.64–2.83 (m, 1H),
3.20 (br s, 1H), 4.33–4.52 (m, 0.5H), 4.58–4.74 (m, 0.5H).
13C NMR: = 14.2, 16.8, 17.8, 18.1, 20.1, 38.3, 38.6, 52.1, 52.2,
76.5, 77.9, 106.6, 107.7.
(E)-4,5-Epoxyheptan-3-one (3d)
Yield: 0.78 g (61%); bp 59–61°C/10 Torr (Lit.17 bp 61–62°C/10
Torr).
1H NMR: = 1.03 (t, 3H, J = 7.0 Hz), 1.08 (t, 3H, J = 7.0 Hz), 1.54–
1.78 (m, 2H), 2.33 (dq, 1H, J = 18.5, 7.0 Hz), 2.50 (dq, 1H, J = 18.5,
7.0 Hz), 3.04 (td, 1H, J = 5.2, 1.8 Hz), 3.24 (d, 1H, J = 1.8 Hz).
Anal. Calcd for C7H14O3: C, 57.51; H, 9.65. Found: C, 57.88; H,
9.39.
(E)-2,3-Epoxyheptan-4-one (3e)
Yield: 0.90 g (70%); bp 61–63°C/10 Torr (Lit.18 bp 44–45°C/3
Torr).
Synthesis 2001, No. 10, 1453–1455 ISSN 0039-7881 © Thieme Stuttgart · New York