832
ZEFIROVA et al.
C 69.31; H 7.02; N 3.11. C27H35NO6. Calculated,
We failed to benzoylate the mixture of isomeric
%: C 69.08; H 7.46; N 2.99
alcohols IV by a standard procedure [3] with benzoyl
chloride in pyridine. However the reaction carried out
with triethylamine and dimethylaminopyridine as
catalyst [4] gave rise to two isomeric benzoyloxy
derivatives V in 74% yield. The structure of the syn-
thsized derivative of benzoyloxyadamantane V was
3-tert-Butyl-5-(4-hydroxyadamantyl)-2,2-di-
methylphenyl-1,3-oxazolidine-3,5-dicarboxylate
(IV) was obtained along procedure [2] from 0.42 g
(0.9 mmol) of compound III by treating with 0.15 g
(4 mmol) of NaBH4 in a mixture of 6 ml of ethyl
ether and 1 ml of MeOH at 0 C. We isolated 0.42 g
(99%) of compound IV as colorless crystals. mp 63
1
confirmed by H NMR spectra.
The final stage of the synthesis consisted in remov-
ing isopropylidene protection in compound V by
formic acid followed by benzoylation of the nitrogen
atom by procedure we had developed earlier [2]. The
target product, 1-(N-benzoylphenylisoserinyl)-4-
benzoyloxyadamantane (VI, isomers ratio 1: 2), was
obtained in 83% yield, and its structure was proved
1
65 C. H NMR spectrum (CDCl3/HMDS), , ppm:
1.11s (9H, t-Bu); 1.68 and 1.75 two s [6H, C(CH3)2];
1.42 2.38 m (14H, skeleton+ OH); 3.74 and 3.92
two t. (1H, CHOH, two isomers 2: 1); 4.32 d (1H,
NCHCHO); 4.93 s (1H, NCHCHO); 7.23 7.37 m
(5H, arom).
1
by elemental analysis and H and 13C APT NMR
5-[4-(Benzoyloxy)adamantyl]-3-tert-butyl-2,2-
dimethyl-phenyl-1,3-oxazolidine-3,5-dicarboxylate
(V). To a solution of 0.078 g (0.64 mmol) of 4-N,N-
dimethylaminopyridine in 40 ml of anhydrous di-
chloromethane at room temperature was added 1 ml
of anhydrous triethylamine, 0.11 g (0.78 mmol) of
benzoyl chloride, and at last 0.3 g (0.64 mmol) of
ester IV. The reaction mixture was stirred for 12 h,
then it was diluted with 30 40 ml of ethyl ether,
washed with 1 N HCl solution (3 25 ml), with
saturated solution of NaHCO3 (20 ml) and water
(20 ml), dried on MgSO4, and evaporated. The
residue was purified by chromatography using as
eluent petroleum ether (boiling within 40 70 C)
ethyl acetate, 9: 1. We obtained 0.27 g (74%) of
spectra. In the 13C APT NMR spectrum the signals of
C1 and C4 from two isomers are observed at 82.36;
81.96 and 74.70; 75.25 ppm. The assignment of
the signals to definite isomer may be done basing
on similarity to the spectra of 2,4-disubstituted
adamantanes [5 7] as we have made in the previous
report or by analogy with the spectra of 1,4-di-
substituted adamantanes [8, 9]. In the first case the
stronger signals at 81.96 and 75.25 should be assign-
ed to the equatorial isomer that should be more stable
according to the calculations of the heats of formation
(see the experimental data). In the second case the
situation should be reversed, and the signals at 81.96
and 75.25 belong to the less stable axial isomer aris-
ing in greater amount. It seems that an unambiguous
assignment of stereoisomers VI can be obtained only
from the X-ray diffraction study.
1
colorless viscous fluid. H NMR spectrum (CDCl3/
HMDS), , ppm: 1.11 s (9H, t-Bu); 1.70 and
1.76 two s [6H, C(CH3)2]; 1.50 2.52 m (13H,
skeleton); 4.36 d (1H, NCHCHO); 4.93 s (1H,
NCHCHO); 5.06 and 5.17 two t (1H, CHOBz, two
isomers, 2: 1); 7.26 8.18 m (10H, arom).
Thus in this study a procedure is developed for
synthesis of 1-(N-benzoylphenylisoserinyl)-4-benzo-
yloxyadamantane in an overall yield 60% with respect
to compound I that makes possible synthesis of a
series of potential biologically active compounds.
1-[1-Hydroxy-2-phenyl-2-(phenylcarboxamido)-
ethylcarbonyloxy]-4-benzoyloxyadamantane (VI)
was prepared by procedure [2] from 0.4 g of com-
pound V in 50 ml of formic acid. The intermediate
product was benzoylated with 0.09 ml (0.77 mmol) of
benzoyl chloride. The final reaction product was
purified by chromatography using as eluent petroleum
ether (boiling within 40 70 C) ethyl acetate, 2.5 : 1.
We obtained 0.31 g (83%) of compound VI as color-
3-tert-Butyl-5-(4-oxoadamantyl)-2,2-dimethyl-
-phenyl-1,3-oxazolidine-3,5-dicarboxylate(III) was
prepared along procedure [2] from 1 g (6 mmol) of
chemantane (I) and 1.28 g (4 mmol) protected amino
acid II in anhydrous dichloromethane. The reaction
product was purified by chromatography using as
eluent ethyl ether petroleum ether (boiling within
40 70 C), 1: 2. We obtained 1.85 g of compound III
as colorless fluid. Yield 99%. 1H NMR spectrum
(CDCl3/HMDS), , ppm: 1.11 s (9H, t-Bu); 1.68 and
1.75 two s [6H, C(CH3)2]; 1.75 2.64 m (13H,
skeleton); 4.35 d (1H, NCHCHO); 4.94 s (1H,
NCHCHO); 7.21 7.37 m (5H, arom). Found, %:
1
less crystals. mp 94 C. H NMR spectrum (CDCl3/
HMDS), , ppm: 1.52 2.52 m (13H, skeleton);
3.31 s (1H, OH); 4.58 d (1H, CHOH); 5.07 and
5.19 two t (1H, CHOBz, two isomers, 2: 1); 5.82 m
(1H, HNCH); 7.05 d (1H, NH); 7.24 8.15 m (15H,
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 39 No. 6 2003