KIRILLOV et al.
580
in 40 ml of anhydrous benzene was added dropwise to
a mixture of 10 g of zinc (prepared as fine turnings)
and 10 ml of anhydrous ethyl acetate. The mixture was
heated for 1 h under reflux, separated from excess zinc
by decanting, and hydrolyzed with water. The organic
phase was separated and dried over anhydrous sodium
sulfate, the solvent was distilled off, and the residue
was twice distilled under reduced pressure. Yield 72%.
bp 107–109°C (13 mm), d420 = 1.0297, nD20 = 1.4528. IR
2.45 m [8H, (CH2)4], 3.62 s (3H, CH3O). Found, %:
C 47.49; H 6.11; Br 28.78. C11H17BrO3. Calculated, %:
C 47.67; H 6.18; Br 28.83.
8-Aryl-9,9-dimethyl-7-oxaspiro[4.5]decane-6,10-
diones. a. Compounds VIIa, VIIb, and VIId. A mix-
ture of 0.03 mol of compound III and 0.023 mol of
the corresponding aldehyde in 20 ml of anhydrous
ethyl acetate was added dropwise with stirring to
a mixture of 6 g of fine zinc turnings, a catalytic
amount of HgCl2, and 10 ml of anhydrous ethyl
acetate. The mixture was heated for 1 h under reflux
and cooled, the liquid phase was separated by
decanting and hydrolyzed with 5% hydrochloric acid,
the organic layer was separated, and the aqueous layer
was extracted with two portions of diethyl ether. The
extracts were combined with the organic phase, dried
over anhydrous sodium sulfate, and evaporated, and
the residue was twice recrystallized from methanol–
ethyl acetate.
1
spectrum, ν, cm–1: 1720, 1735, 1750 (C=O). H NMR
spectrum, δ, ppm: 0.91 d (6H, CH3), 1.25–2.21 m [8H,
(CH2)4], 2.61 m (1H, CHCO), 3.54 s (3H, CH3O).
Found, %: C 66.52; H 9.08. C11H18O3. Calculated, %:
C 66.64; H 9.15.
Methyl 2,2-dimethyl-3-oxo-3-cyclopentylpropio-
nate (IX) was synthesized as described above for
compound II from methyl α-bromoisobutyrate and
cyclopentanecarbonyl chloride. Yield 64%. bp 94–
96°C (6 mm), d420 = 1.0277, nD20 = 1.4521. IR spectrum,
1
ν, cm–1: 1720, 1735, 1750 (C=O). H NMR spectrum,
b. Compounds VIIc and VIIe. A solution of
0.03 mol of compound III in 10 ml of ethyl acetate
was added with stirring to a mixture of 6 g of activated
zinc (prepared as fine turnings) and 10 ml of anhy-
drous ethyl acetate. The mixture was heated for 30 min
under reflux, the liquid phase was separated by
decanting, and 0.023 mol of aldehyde Vc or Ve was
added. The subsequent procedure was the same as in a.
δ, ppm: 0.85–2.03 m [8H, (CH2)4], 1.23 s (6H, CH3),
2.55–2.95 m (1H, CHC=O), 3.62 s (3H, CH3O).
Found, %: C 66.69; H 9.24. C11H18O3. Calculated, %:
C 66.64; H 9.15.
Methyl 1-(2-bromoisobutyryl)cyclopentane-
carboxylate (III). Bromine, 0.11 mol, was added with
stirring to a solution of 0.1 mol of compound II in
25 ml of acetic acid. The mixture was heated for 1.5 h
on a water bath, the solvent was distilled off, and
the residue was distilled under reduced pressure. Yield
10-Aryl-7,7-dimethyl-9-oxaspiro[4.5]decane-6,8-
diones XIIIa–XIIIc were synthesized from compound
X, following the procedures described above in a
(XIIIa and XIIIb) and b (XIIIc).
The yields, melting points, IR and 1H NMR spectral
parameters, and elemental analyses of compounds
VIIa–VIIe and XIIIa–XIIIc are given in table.
86%. bp 127–129°C (7 mm), d420 = 1.3491, nD20
=
1.4911. IR spectrum, ν, cm–1: 1715, 1735, 1755, 1760
1
(C=O). H NMR spectrum, δ, ppm: 1.83 s (6H, CH3),
1.17–2.53 m [8H, (CH2)4], 3.60 s (3H, CH3O). Found,
%: C 47.51; H 6.02; Br 28.95. C11H17BrO3. Calculated,
%: C 47.67; H 6.18; Br 28.83.
Methyl 3-(1-bromocyclopentyl)-2,2-dimethyl-3-
oxopropionate (X) was synthesized from ester IX as
described above for compound III. Yield 58%.
bp 133–136°C (9 mm), mp 35–36°C (from petroleum
ether). IR spectrum, ν, cm–1: 1715, 1740, 1765 (C=O).
1H NMR spectrum, δ, ppm: 1.45 s (6H, CH3), 1.55–
REFERENCES
1. Kirillov, N.F., Shchepin, V.V., and Litvinov, D.N., Russ.
J. Org. Chem., 2000, vol. 36, p. 979.
2. Kirillov, N.F. and Shchepin, V.V., Russ. J. Org. Chem.,
2001, vol. 37, p. 811.
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 40 No. 4 2004
Kirillov
