Russian Journal of Organic Chemistry, Vol. 38, No. 2, 2002, pp. 295 296. Translated from Zhurnal Organicheskoi Khimii, Vol. 38, No. 2, 2002,
pp. 316 317.
Original Russian Text Copyright
2002 No, Butov, Mokhov, Parshin.
SHORT
COMMUNICATIONS
Preparation of -Adamantyl-substituted Aliphatic Ketones
B. I. No, G. M. Butov, V. M. Mokhov, and G. Yu. Parshin
Volgograd State Technical University, Volgograd, 400131 Russia
Kuban State University, Krasnodar, 350040 Russia
Received January 9, 2001
The known synthetic methods for ketones with
adamantyl fragment [1 4] are not fit for preparation
of branched products. They are also multistage,
provide the target products in low yield, require
application of Grignard reagents or strong acids
[1, 2].
The optimal condition for condensation of compound
I with ketones is to perform the reaction in the
medium of the original ketone at the molar ratio
1,3-dehydroadamantane to ketone equal to 1: 4 6.
The yield of condensation products varies within
65 75%.
Compounds IIa e were purified by vacuum distilla-
tion. Crystalline substances IIc e were additionally
recrystallized from 2-propanol. The structure of
compounds obtained IIa e was proved by IR,
1H NMR, and mass spectroscopy. Their purity was
confirmed by GC-MS method.
With the goal to develop a convenient preparation
method for
-adamantyl-substituted ketones we
carried out condensation of 1,3-dehydroadamantane
(I) with aliphatic ketones at the -carbon.
1-(1-Adamantyl)acetone (IIa). The ketone prop-
erties are consistent with the published data [4].
1-(1-Adamantyl)-3,3-dimethyl-2-butanone (IIb).
Yield 70%. bp 181 183 C (8 mm Hg). IR spectrum,
II, R1 = R2 = H, R3 = Me (a); R1 = R2 = H, R3 =
t-Bu (b); R1 = H, R2 = R3 = Me (c); R1 = H, R2 =
Me, R3 = Et (d); R1 = R2 = Me, R3 = i-Pr (e).
1
cm : 2840 2900 (CH, Ad), 1712 (C O), 1456 (CH).
1H NMR spectrum, , ppm: 0.88 m [9H, C(CH3)3],
1.62, 1.90, 2.08 three s (15H, Ad), 2.22 m [2H,
CH2C(O)]. Found, %:C 82.03; H 11.21. M 234.
C16H26O. Calculated, %: C 81.99; H11.18. M 234.38.
The reaction was performed in the medium of 4 6-
fold excess of the initial ketone at 60 120 C within
6 12 h.
3-(1-Adamantyl)-2-butanone (IIc). Yield
72%. mp 41 C, bp 155 C (10 mm Hg). IR spectrum,
This reaction is possible obviously because of
unique properties of hydrocarbon I for his structure
ensures its high reactivity with respect to a wide
range of OH-, NH-, SH, and CH-acids. The reaction
of compound I with aliphatic ketones that are relative-
ly weak CH-acids (®K 20) is important for pre-
parative chemistry, and we are the first who has
established this fact. We found that the yield of the
target ketones is affected by reaction temperature,
duration, and by the structure of the original ketone.
The reaction of methyl ethyl ketone with 1,3-de-
hydroadamantane (I) gave rise (79 C, 12 h) mainly to
3-(1-adamantyl)-2-butanone, resulting from addition
at the methylene and not methyl group.
1
cm : 2840 2900 (CH, Ad), 1704 (C O), 1416 1455
1
(CH). H NMR spectrum, , ppm: 0.94m (3H, CH3),
1.46, 1.63, 1.98 three s (15H, Ad), 2.1 m (3H, CH3),
2.32 m (1H, CH). Found, %: C 81.54; H 10.81. M
206. C14H22O. Calculated, %: C 81.50; H 10.75. M
206.32.
2-(1-Adamantyl)-3-pentanone (IId). Yield 69%.
1
bp 129 C (4 mm Hg), mp 25 C. IR spectrum, cm :
2840 2900 (CH, Ad), 1712 (C O), 1456 (CH).
Found, %: C 81.79; H 11.02. M 220. C15H24O.
Calculated, %: C 81.76; H 10.98. M 220.18.
4-(1-Adamantyl)-2,4-dimethyl-3-pentanone (IIe).
Yield 75%. bp 127 C (1 mm Hg), mp 25 C. IR
1070-4280/01/3802-295$27.00 2002 MAIK Nauka/Interperiodica
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