Tokuyasu et al.
7
(120 mg, 36%) was isolated by elution with diethyl ether-
hexane (10:90). Subsequent elution with diethyl ether-hexane
15:85) gave the hydroperoxides 8 (88 mg, 22%). The hydro-
mmol), bis(acetylacetonato)cobalt(II) (13 mg, 0.050 mmol) and
ethanol (10 mL), and then the flask was again charged with
dioxygen. Triethylsilane (230 mg, 2.0 mmol) was added via
1.0-mL gastight syringe, and the reaction mixture was stirred
vigorously under oxygen atmosphere at room temperature.
After the mixture was stirred for 6 h, the solvent was
evaporated under reduced pressure. Then, the components of
the residue were separated by column chromatography on
silica gel. Elution with diethyl ether-hexane (5:95) gave a
mixture of the diene 17 and the corresponding triethylsilyl
peroxide 18. Subsequent elution with diethyl ether-hexane
(15:85) gave the unsaturated hydroperoxide 19 (55 mg, 47%
based on consumed 17). The hydroxy-substituted 2,3-dioxabi-
cyclo[3.3.1]nonane derivative 20 (26 mg, 20% based on con-
sumed 17) was obtained from elution with diethyl ether-
hexane (25:75). After treatment of the mixture of 17 and 18
with a drop of concentrated HCl in MeOH (1 mL) for 1 min,
(
peroxide 7 (70 mg, 0.41 mmol), which was labile even in a
refrigerator, decomposed within 10 days to afford a complex
mixture containing the endoperoxide 8 (43 mg, 52%). There-
fore, satisfactory elemental analysis data could not be ob-
tained. The reaction of 7 with Ph
C for 5 min gave the corresponding alcohol, 1-methyl-1-(4-
3 2 2
P (1.2 equiv) in CH Cl at 0
°
methyl-3-cyclohexenyl)ethanol (26) in 94% yield, which showed
the expected elemental analysis data.
When the same reaction was conducted for 24 h, followed
by column chromatography on silica gel (elution with diethyl
ether-hexane, 2:98), a mixture of the triethylsilyl peroxides
1
1, 12, and 13 (459 mg) was obtained. After treatment of the
mixture with a drop of concentrated HCl in methanol (2 mL)
for 5 min, components of the reaction mixture were separated
by column chromatography on silica gel. The unsaturated
hydroperoxide 7 (28 mg, 8%) was isolated by elution with
diethyl ether-hexane (10:90). Subsequent elution with diethyl
ether-hexane (15:85) gave the hydroperoxides 8 (91 mg, 23%).
The third fraction (elution with ether-hexane. 25:75) con-
tained 4-(1-hydroperoxy-1-methylethyl)-1-methylcyclohexyl hy-
droperoxide (9A) (36 mg, 9%). Further elution with ether-
hexane (25:75) gave the isomeric bis-hydroperoxide 9B (32 mg,
4
solid sodium bicarbonate and anhydrous MgSO were added.
The reaction mixture was stirred for an additional 5 min, and
then solid materials were removed by filtration over Celite.
After evaporation of the solvent under reduced pressure,
components of the residue were separated by column chroma-
tography on silica gel. The diene 17 (106 mg) was recovered
by elution with diethyl ether-hexane (5:95) (conv 49%).
Subsequent elution with diethyl ether-hexane (15:85) gave
the unsaturated hydroperoxide 19 (20 mg, 17% based on
8
%).
3
consumed 17). The reduction of 19 with Ph P (1 equiv) in
1
-Meth yl-1-(4-m eth yl-3-cycloh exen yl)eth yl h yd r op er -
1
benzene gave the corresponding alcohol, [3-(1-hydroxy-1-
methylethyl)cyclohexylidene]acetic acid ethyl ester (27), quan-
titatively.
oxid e (7): oil; H NMR δ 1.1-1.3 (m, 1 H), 1.19 (s, 6 H), 1.65
1
3
(
s, 3 H), 1.7-2.1 (m, 6 H), 5.3-5.4 (m, 1 H), 7.48 (s, 1 H);
), 21.5 (CH ), 23.3 (CH ), 23.9 (CH ), 26.6
), 40.3 (CH), 85.0 (C), 120.5 (CH), 134.0 (C).
-Meth yl-1-(4-m eth yl-3-cycloh exen yl)eth a n ol (26): oil;
H NMR δ 1.17 (s, 3 H), 1.19 (s, 3 H), 1.1-1.3 (m, 1 H), 1.4-
.6 (m, 2 H), 1.65 (s, 3 H), 1.7-2.1 (m, 5 H), 5.3-5.4 (m, 1 H);
C NMR δ 23.3 (CH
CH ), 30.9 (CH ), 44.9 (CH), 72.7 (C), 120.5 (CH), 133.9 (C).
18O: C, 77.87; H, 11.76. Found: C, 77.85;
C
NMR δ 21.0 (CH
(
3
3
3
2
CH
2
), 30.8 (CH
2
2-Hydr oxy-2-(4,4-dim eth yl-2,3-dioxabicyclo[3.3.1]n on yl)-
1
a cetic a cid eth yl ester (20): oil (1:1 mixture of two stereo-
1
1
isomers); H NMR δ 1.2-2.4 (m, 18 H), 3.00 (d, J ) 8.3 Hz;
1
H-D exchange in D
in D
Hz; s in D
14.3 (CH ), 20.2 (CH
), 26.4 (CH ), 29.4 (CH
), 35.25 (CH), 35.29 (CH), 61.8 (CH
2
O) + 3.05 (d, J ) 7.6 Hz; H-D exchange
1
3
), 23.9 (CH
2
), 26.1 (CH
3
), 26.8 (CH
2
), 27.3
2
O) (1 H), 3.90 (d, J ) 7.6 Hz; s in D O) + 3.95 (d, J ) 8.0
2
3
13
(
3
2
2
O) (1 H), 4.2-4.4 (m, 2 H); C NMR δ 14.2 (CH
3
),
Anal. Calcd for C10
H, 11.73.
H
3
2
, 2C), 23.5 (CH
3
, 2C), 24.9 (CH
3
, 2C), 26.4
(CH
CH
2
2
2
2
), 30.2 (CH
2
), 30.4 (CH
2
), 31.0
), 75.6
(
2
), 62.0 (CH
2
(
1S,5S,8S)-4,4,8-Tr im eth yl-2,3-dioxabicyclo[3.3.1]n on an -
1
(CH), 75.8 (CH), 80.8 (C), 80.9 (C), 81.38 (C), 81.42 (C), 171.7
8
3
-yl h yd r op er oxid e (8): oil; H NMR δ 1.16 (s, 3 H), 1.42 (s,
H), 1.48 (s, 3 H), 1.6-2.0 (m, 5 H), 2.2-2.4 (m, 2 H), 4.1-4.2
+
+
(
C), 171.8 (C); LRMS (EI) m/z (rel int) 258 (M ) (14), 155 (M
1
3
- CH(OH)CO Et) (100). Anal. Calcd for C H O : C, 60.45;
(
(
8
m, 1 H), 7.94 (s, 1 H); C NMR δ 21.5 (CH
CH ), 24.5 (CH ), 24.6 (CH ), 31.6 (CH
1.6 (C), 83.1 (C). Anal. Calcd for C10
Found: C, 59.58; H, 8.94.
-(1-H yd r op er oxy-1-m et h ylet h yl)-1-m et h ylcycloh ex-
3
), 23.6 (CH
), 32.4 (CH), 77.6 (CH),
: C, 59.39; H, 8.97.
2
), 24.4
2
13 22
5
H, 8.58. Found: C, 60.18; H, 8.44.
2
3
3
2
H
18
O
4
[3-(1-Hydr oper oxy-1-m eth yleth yl)cycloh exyliden e]ace-
tic a cid eth yl ester (19): oil (a ca. 2:1 mixture of two
1
4
stereoisomers); H NMR δ 1.0-2.4 (m, 17 H), 3.83 (br t, J )
yl h yd r op er oxid e (9A): colorless solid, mp 78-82 °C (from
12.7 Hz, 1 H), 4.0-4.2 (m, 2 H), 5.61 (s) + 5.63 (s, major) (1
1
13
hexane); H NMR δ 1.19 (s, 6 H), 1.29 (s, 3 H), 1.15-1.80 (m,
H), 7.95 (s, major) + 8.87 (s) (1 H); C NMR (major isomer) δ
7
H), 2.01 (br d, J ) 10.8 Hz, 2 H), 7.40 (s, 1 H), 7.51 (s, 1 H);
C NMR δ 20.4, 21.7, 24.2, 34.5, 44.0, 83.0, 84.7. Anal. Calcd
14.2, 20.8, 21.9, 26.9, 27.1, 29.4, 38.5, 46.1, 59.6, 84.2, 113.7,
162.8, 166.9; the following additional signals were assigned
to the minor isomer in the 13C NMR spectrum, δ 19.8, 22.6,
1
3
for C10
20 4
H O : C, 58.80: H, 9.87. Found: C, 58.72: H, 9.92.
2
7.9, 28.9, 31.5, 37.8, 46.3, 60.0, 84.1, 112.1, 164.5, 167.7.
Bis-h yd r op er oxid e 9B: colorless solid, mp 85-88 °C (from
1
hexane); H NMR δ 1.19 (s, 6 H), 1.10-1.80 (m, 7 H), 1.29 (s,
3
2
[3-(1-H yd r oxy-1-m et h ylet h yl)cycloh exylid en e]a cet ic
H), 1.78 (br d, J ) 10.4 Hz, 2 H), 7.20 (s, 2 H); 13C NMR δ
0.4, 21.7, 24.3, 34.5, 44.0, 83.0, 84.6. Anal. Calcd for
a cid et h yl est er (27): oil (ca. 2:1 mixture of two stereo-
1
isomers); H NMR δ 1.2-2.4 (m, 18 H), 3.82 (br t, J ) 13.5
C
10
H
20
O
4
: C, 58.80: H, 9.87. Found: C, 58.95: H, 9.70.
Sp on ta n eou s Tr a n sfor m a tion of Un sa tu r a ted Hyd r o-
p er oxid e 7 to En d op er oxid e 8 in CDCl . A solution of the
unsaturated hydroperoxide 7 (32 mg, 0.18 mmol) was dissolved
Hz, major) + 3.98 (br t, J ) 12.2 Hz) (1 H), 4.10 (q, J ) 7.2
Hz, 2 H), 5.61 (s, 1H); 13C NMR δ 14.2 (2 C), 26.5, 26.8 (2 C),
27.0, 27.1 (2 C), 27.3, 27.7, 29.3, 30.8, 37.6, 38.7, 50.3, 50.8,
59.4, 59.5, 72.3, 72.4, 113.3, 113.6, 162.9, 163.1, 166.7, 166.8.
3
1
in CDCl
3
(1 mL), and then the H NMR spectra of this solution
Anal. Calcd for C13
H, 9.90.
22 3
H O : C, 68.99; H, 9.80. Found: C, 68.68;
were periodically measured. To make the uptake of the oxygen
molecule easy, the cap of the NMR tube was removed (except
for the measurement of the NMR spectra) and instead the tube
was covered by aluminum foil very loosely. After 7 days the
solvent was evaporated and the residue was separated by
column chromatography on silica gel. Elution with ether-
hexane (8:92) gave the starting material 7 (11 mg, conv 66%).
Subsequent elution with ether-hexane (15:85) gave the cyclic
peroxide 8 (11 mg, 44% based on the consumed 7).
Co(a ca c) -Ca ta lyzed Tr a n sfor m a tion of Un sa tu r a ted
2
Hyd r op er oxid e 19 to th e En d op er oxid e 20 in EtOH. A
mixture of hydroperoxide 19 (153 mg, 0.63 mmol), Co(acac)2
(8.0 mg, 0.031 mmol), and triethylsilane (146 mg, 1.3 mmol)
in ethanol (6.3 mL) was stirred at room temperature for 24 h.
After the conventional workup, the mixture of the products
was separated by column chromatography on silica gel. Elution
with ether-hexane (5:95) gave the peroxide 18 as an admix-
ture with a small amount of contaminants. The hydroperoxide
19 (26 mg) was recovered (conv 83%) from the second fraction
(elution with ether-hexane, 15:85). Subsequent elution with
2
P er oxid a tion of Dien es w ith Co(a ca c) in EtOH. The
reaction of 17 is representative. Into a two-neck 50-mL flask,
charged with dioxygen, were added diene 17 (210 mg, 1.0
7
366 J . Org. Chem., Vol. 68, No. 19, 2003