PREPARATION OF -METHYL-SUBSTITUTED DIALKYL KETONES
1183
ium hydroxide in a Faworsky flask was placed into
an oil bath preliminary heated to 120 130 C. The
reaction product, 3-methylbutan-2-one (IIa) contain-
ing 4% of pentan-2-one (GLC), was distilled off in
the course of reaction and collected. Yield 1.3 g
(65%), bp 93 96 C (publ. bp 93 C [7]).
Ratio of products obtained by cyclopropanols
isomerization effected by potassium hydroxide
Run Compd.
Solvent
Ratio of
ketones (II):(III)
Yield,
%
no.
no.
1
Ia
Ib
Ib
Ib
Ib
Ib
Ic
96: 4
99.5 : 0.5
98: 2
100: 0
99: 1
96: 4
90: 10
99.5:0.5
65
General procedure of cyclopropanols isomeriza-
tion. To a solution of 3 mmol of substituted cyclo-
propanol in 4 ml of solvent was added 1 ml of 20%
water solution or 0.2 0,4 g of alkali powder, and this
mixture was stirred at room temperature. The reac-
tion course was monitored by TLC. On completion
of the reaction the organic layer was separated from
alkali and analyzed by GLC under the following con-
ditions: chromatograph LKhM-8MD, detector
katharometer, carrier gas helium, columns 2000
3 mm, stationary phases 5%OV-1 on Chromaton
N-Super (0.16 0.20 mm) and 5% SE-30 on Inerton
2a
3a
4a
5a
6
THF
DMF
MeOH
Pentane
Pentane
MeOH
THF
55
56
75
7
8
Id
a
Reaction mixtures were only analyzed by GLC.
The author is grateful to his scientific promoter
Professor O. G. Kulinkevich (Belorussian State
University, Minsk) for fruitful discussions that
provided the possibility to carry out this study.
1
AW-HMDS (0.20 0.25 mm). H NMR spectra were
recorded from solutions in CCl4 on spectrometer
Tesla BS-467A (60 MHz), internal reference HMDS.
Multiplicity and chemical shifts of the signals in the
spectra of ketones obtained were consistent with the
published data.
REFERENCES
1. Yanovskaya, L.A., Dombrovskii, V.A., and Khu-
sid, A.Kh., Tsiklopropany s funktsional,nymi grup-
pami (Cyclopropanes with Functional Groups), Mos-
cow: Nauka, 1980; Gibson, D.H. and De Puy, C.H.,
Chem. Rev., 1974, vol. 74, no. 6, pp. 605 624;
De Puy C.H., Fortsch. Chem. Forsch., 1973, vol. 40,
pp. 73 101.
2. Riley, R.G., Silverstein, R.M., and Moser, J.C.,
Science, 1974, vol. 183, no. 3, pp. 760 765.
3. Kulinkovich, O.G. and de Meijere, A., Chem. Rev.,
2000, vol. 100, no. 8, pp. 2789 2834.
4. Savchenko, A.I., Cand. Sci. (Chem.) Dissertation,
Minsk, 1995.
5. Gunther, H., NMR Spectroscopy, Chichester, Wiley.
Dretsch, E., Seibl, J., Simon, W., and Clerc, T.,
Tables of Spectral Data for Determination of Organic
Compouns, Berlin: Springer, 1983.
2-Methylpentan-2-one (IIb) (see table, run no.
6). A mixture of 3.43 g of 1-ethyl-2-methylcyclo-
propanol (Ib) and 2.96 g of KOH powder in 35 ml of
pentane was stirred for 24 h. The workup was as
described above. After evaporation of the solvent the
residue was distilled. Yield of 2-methylpentan-3-one
(IIb) containing 4% of hexan-3-one (IIIb) (GLC)
1.9 g (55%), bp 109 111 C (publ. bp 106 110 C [8]).
3-Methylheptan-4-one (IIc) (see table, run no. 7).
A mixture of 2.88 g of 1-propyl-2-ethylcyclopropanol
(Ic) and 0.87 g of KOH powder in 28 ml of MeOH
was kept for 24 h at room temperature and then
worked up as above. We obtained 1.63 g (56%) of
3-methylheptan-4-one (IIc) containing 10% of octane-
4-one (IIIb) (GLC), bp 155 158 C (publ. bp 152
154 C at 740 mm Hg [9]).
6. De Puy C.H., van Lanen R.J., J. Org. Chem., 1974,
vol. 39, no. 23, pp. 3360 3365.
7. Svoistva organicheskikh soedinenii (Properties of
Organic Compounds), Potekhin, A.A. Ed., Lenin-
grad: Khimiya, 1984.
8. Libman, N.M. and Shandubina, O.N., Zh. Org.
Khim., 1984, vol. 20, no. 12, pp. 2517 2521.
9. Stutsman, P.S. and Adkins, H., J. Am. Chem. Soc.,
1939, vol. 61, no. 12, pp. 3303 3306.
4-Methylheptan-3-one (IId) (see table, run no. 8).
A mixture of 1.66 g of 1-ethyl-2-propylcyclopropanol
(Id) and 0.75 g of KOH powder in 20 ml THF was
stirred for 24 h, then filtered through silica gel bed,
the latter was washed with ether, and after distilling
off the solvent the residue was distilled. Yield of
4-methylhepten-3-one (IId) 1.25 g (75%), bp 155
157 C (publ. 52 55 C at 25 mm Hg [10]).
10. Meyers, A.I., Kovelesky, A.C., and Jurjevich, A.F.,
J. Org. Chem., 1973, vol. 38, no. 12, pp. 2136 2143.
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 37 No. 8 2001