2
634 J . Org. Chem., Vol. 62, No. 8, 1997
Notes
Sch em e 2
was added aqueous 2 N HCl (20 mL). After stirring for 1 h, the
mixture was extracted with EtOAc (3 × 20 mL). The organic
layer was washed with water and brine and dried over MgSO
4
.
The crude products 3a -e were purified by column chromatog-
raphy (hexane:EtOAc ) 6-12:1).
2
-Hexylcyclobu ta n on e (3a ): oil (83%); IR (neat) 1750
-
1 1
(
1
(
1
CdO) cm ; H NMR (CDCl
.35 (br, 8H), 1.44-1.50 (m, 1H), 1.60-1.70 (m, 2H), 2.13-2.22
m, 1H), 2.87-2.96 (m, 1H), 2.97-3.07 (m, 1H), 3.23-3.34 (m,
3
) δ 0.88 (t, J ) 6.8 Hz, 3H), 1.19-
+
H); MS m/ z (rel intensity) 154 (M ).
-P en tylcyclop en ta n on e (3b): oil (86%); IR (neat) 1740
2
-
1 1
(
1
(
CdO) cm ; H NMR (CDCl
3
) δ 0.88 (t, J ) 6.8 Hz, 3H), 1.19-
.36 (br, 7H), 1.47-1.57 (m, 1H), 1.71-1.83 (m, 2H), 1.96-2.06
m, 2H), 2.08-2.15 (m, 1H), 2.17-2.34 (m, 2H); MS m/ z (rel
+
intensity) 154 (M ).
pentanone via hydrazone method and Baeyer-Villiger
2-Hep tylcyclop en ta n on e (3c): oil (73%); IR (neat) 1740
-
1 1
(
CdO) cm ; H NMR (CDCl
1.36 (br, 11H), 1.47-1.57 (m, 1H), 1.73-1.83 (m, 2H), 1.97-2.06
m, 2H), 2.08-2.15 (m, 1H), 2.21-2.34 (m, 2H); MS m/ z (rel
3
) δ 0.88 (t, J ) 6.4 Hz, 3H), 1.19-
oxidation with MMPP, was allowed to react with LDA
8
in THF at -78 °C and then with diphenyl disulfide to
(
give the mixture of diastereomers of 2-(phenylthio)-5-
+
intensity) 182 (M ).
-Un d ecylcyclop en ta n on e (3d ): solid (65%); mp 24 °C; IR
(Nujol) 1745 (CdO) cm-1
H NMR (CDCl ) δ 0.88 (t, J ) 6.8
Hz, 3H), 1.19-1.36 (br, 19H), 1.47-1.57 (m, 1H), 1.71-1.83 (m,
H), 1.96-2.06 (m, 2H), 2.07-2.18 (m, 1H), 2.20-2.33 (m, 2H);
decanolide (5) in 61% yield. After oxidation of 5 with
2
NaIO
5% yield.
In summary, MMPP was found to be an effective
4
, thermal elimination gave massoia lactone (6) in
;
1
3
9
2
+
MS m/ z (rel intensity) 239 (M + 1).
oxidant of 2-alkylcycloalkanones to the corresponding
lactones. Using this reaction, some lactonic flavors and
pheromones were prepared.
2
-Bu tylcycloh exa n on e (3e): oil (67%); IR (neat) 1715 (CdO)
-
1 1
cm ; H NMR (CDCl
3
) δ 0.89 (t, J ) 6.7 Hz, 3H), 1.17-1.44 (m,
6
2
H), 1.61-1.89 (br, 4H), 2.00-2.13 (m, 2H), 2.24-2.32 (m, 2H),
+
.36-2.41 (m, 1H); MS m/ z (rel intensity) 154 (M ).
Gen er a l P r oced u r e for th e Ba eyer -Villiger Oxid a tion
Exp er im en ta l Section
of 2-Alk ylcycloa lk a n on es 3 Usin g MMP P . A typical proce-
dure is described for the synthesis of 5-decanolide (4b): To a
solution of 2-pentylcyclopentanone (3b) (0.5 mmol, 0.077 g) in
Gen er a l. 1H NMR spectra were taken at 400 MHz in CDCl
solvent and recorded in parts per million (ppm, δ) downfield from
internal tetramethylsilane (Me Si). Column chromatography
3
4
MeOH (2.0 mL)-H O (2.0 mL) were added MMPP (1.0 mmol,
2
was performed using silica gel 60 (230-400 mesh), and thin-
layer chromatography (TLC) was performed on silica gel 60
plates (F254). THF was dried and deoxygenated by distillation
from potassium benzophenone under an argon atmosphere just
before use. Benzene and toluene were purified by distillation
0.49 g) and NaHCO (1.0 mmol, 0.084 g) at room temperature.
3
After stirring for 24 h, the reaction mixture was diluted with
water (10 mL) and ethyl acetate (50 mL). The organic layer was
washed with brine and dried over MgSO . Evaporation of the
4
solvents and bulb-to-bulb distillation (145 °C/9 mmHg) gave
5-decanolide (4b) (0.47 mmol, 0.0797 g, 94%). 4b was character-
2
over CaCl . Diisopropylamine was dried by distillation from
1
potassium hydroxide. n-Butyllithium as a ca. 1.6 M hexane
solution was titrated with sec-butyl alcohol using o-phenanthro-
line as an indicator just before use. The other organic com-
pounds were commercial products of the highest available purity.
Gen er a l P r oced u r e for t h e P r ep a r a t ion of Cyclo-
ized by H NMR, MS, IR, and GC comparsion with an authentic
sample.
4-Deca n olid e (4a ): oil (95%); bp 150 °C/10 mmHg; IR (neat)
1785 (CdO) cm-1
1
; H NMR (CDCl ) δ 0.89 (t, J ) 6.8 Hz, 3H),
3
1.29-1.46 (br, 8H), 1.56-1.63 (m, 1H), 1.70-1.75 (m, 1H), 1.81-
1.91 (m, 1H), 2.29-2.37 (m, 1H), 2.51-2.55 (m, 1H), 4.46-4.53
a lk a n on e N,N-Dim et h ylh yd r a zon es 2a -c. In
a flask
equipped with a trap to remove water, the mixture of cycloal-
kanone 1 (100 mmol), N,N-dimethylhydrazine (120 mmol, 9.12
mL), trifluoroacetic acid (0.05 mL), and benzene (40 mL) was
added. The mixture was heated under reflux for 5 h and then
cooled to room temperature. The reaction mixture was diluted
with ether (200 mL) and water (50 mL). The organic layer was
(m, 1H); MS m/ z (rel intensity) 171 (M
+
+ 1).
5-Deca n olid e (4b): oil (94%); bp 145 °C/9 mmHg; IR (neat)
1740 (CdO) cm-1
H NMR (CDCl ) δ 0.89 (t, J ) 6.7 Hz, 3H),
1.29-1.93 (m, 12H), 2.40-2.48 (m, 1H), 2.55-2.61 (m, 1H),
4.27-4.30 (m, 1H); MS m/ z (rel intensity) 171 (M + 1).
5-Dod eca n olid e (4c): oil (98%); bp 130 °C/2 mmHg; IR (neat)
1740 (CdO) cm-1
H NMR (CDCl ) δ 0.88 (t, J ) 6.8 Hz, 3H),
1.28-1.93 (br, 16H), 2.40-4.49 (m, 1H), 2.55-2.61 (m, 1H),
4.26-4.27 (m, 1H); MS m/ z (rel intensity) 199 (M + 1).
5-Hexa d eca n olid e (4d ): solid (60%); mp 38 °C; IR (Nujol)
1
;
3
+
washed with brine and dried over MgSO
4
.
The filtrate was
;
1
3
concentrated with a rotary evaporator. The residue was purified
by distillation under reduced pressure.
+
Cyclobu ta n on e N,N-d im eth ylh yd r a zon e (2a ): oil (65%);
-
1
1
-1 1
bp 150 °C/760 mmHg; IR (neat) 1665 (CdN) cm
;
H NMR
) δ 1.94-2.02 (m, 2H), 2.59 (s, 6H), 2.90-3.00 (m, 4H);
C NMR (CDCl
1745 (CdO) cm ; H NMR (CDCl ) δ 0.88 (t, J ) 6.8 Hz, 3H),
3
(
CDCl
3
1.19-1.29 (br, 17H), 1.49-1.60 (m, 3H), 1.66-1.74 (m, 1H),
1.81-1.92 (m, 3H), 2.40-2.48 (m, 1H), 2.55-2.63 (m, 1H), 4.26-
1
3
3
) δ 14.38, 35.14, 35.31, 46.80, 160.36; MS m/ z
+
+
(
rel intensity) 112 (M ).
4.29 (m, 1H); MS m/ z (rel intensity) 255 (M + 1).
Cyclop en ta n on e N,N-d im eth ylh yd r a zon e (2b): oil (91%);
6
-Deca n olid e (4e): oil (92%); bp 150 °C/10 mmHg; IR (neat)
-1 1
bp 58 °C/17 mmHg; IR (neat) 1660 (CdN) cm ; H NMR (CDCl
3
)
-1 1
1
1
2
3
735 (CdO) cm ; H NMR (CDCl ) δ 0.89 (t, J ) 6.8 Hz, 3H),
δ 1.70-1.81 (m, 4H), 2.37 (t, J ) 7.2 Hz, 2H), 2.45 (t, J ) 7.3
.23-1.42 (br, 7H), 1.47-1.62 (m, 2H), 1.67-1.94 (m, 3H), 2.40-
.48 (m, 1H), 2.55-2.61 (m, 1H), 4.26-4.30 (m, 1H); MS m/ z
+
Hz, 2H), 2.53 (s, 6H); MS m/ z (rel intensity) 126 (M ).
Cycloh exa n on e N,N-d im eth ylh yd r a zon e (2c): oil (90%);
(rel intensity) 170 (M
+
).
-1 1
3
bp 75 °C/17 mmHg; IR (neat) 1655 (CdN) cm ; H NMR (CDCl )
2
-(P h en ylth io)-5-d eca n olid e (5). To a THF (5 mL) solution
δ 1.63-1.71 (m, 6H), 2.24 (t, J ) 6.4 Hz, 2H), 2.44 (s, 6H), 2.51
of diisopropylamine (5.5 mmol, 0.78 mL) in a dried reaction flask
was added n-BuLi in hexane (6.0 mmol, 3.8 mL) at -5 °C under
an argon atmosphere. After 0.5 h, lactone 4b (5 mmol, 0.77 g)
was added at -78 °C. After 1 h, diphenyl disulfide (7.0 mmol,
0.76 g) in THF (2 mL) was added at -78 °C, and stirring was
continued for 20 h at room temperature. The reaction was
quenched with water, and the mixture was diluted with ether
(50 mL). The organic layer was washed with aqueous 0.1N HCl,
aqueous saturated NaHCO , and brine and dried over MgSO .
+
(
t, J ) 6.1 Hz, 2H); MS m/ z (rel intensity) 140 (M ).
Gen er a l P r oced u r e for t h e P r ep a r a t ion of 2-Alk yl-
cycloa lk a n on es 3a -e. To a solution of cycloalkanone N,N-
dimethylhydrazone 2 (10.0 mmol) in THF (20 mL) was added
n-BuLi in hexane (10.5 mmol, 6.8 mL) at -5 °C under an argon
atmosphere. After the mixture stirred for 1 h at this temper-
ature, alkyl bromide (10.3 mmol) was added, and stirring was
continued for 20 h at room temperature. To the reaction mixture
3
4
The crude product 5 was purified by column chromatography
(hexane:EtOAc ) 4:1) (3.03 mmol, 0.84 g, 61%): solid; mp 48
(
8) Trost, B. M.; Salzmann, T. N.; Hiroi, K. J . Am. Chem. Soc. 1976,
-
1 1
9
8, 4887.
3
°C; IR (Nujol) 1715 (CdO) cm ; H NMR (CDCl ) δ 0.87-0.98