TRISHIN et al.
1492
a 1:1 mixture of petroleum ether (bp 70–100°C) and
toluene. The extract was cooled to 10°C, and the
precipitate was filtered off and dried in air. The crude
product was a yellowish powder with mp 230–257°C.
It was recrystallized twice from ethanol to obtain
a loose white powder with mp 251–252°C; published
data [5]: mp 256–258°C. According to the H NMR
data, the product contained ≥95% of the main
substance.
irradiation, graphite monochromator, ω-scanning,
2θmax = 58°). The structure was solved by the direct
method and was refined by the least-squares procedure
in full-matrix anisotropic approximation with respect
to F2hkl. The positions of hydrogen atoms were calculat-
ed on the basis of geometry considerations and were
refined in isotropic approximation according to the
riding model. The final divergence factors were R1 =
0.0577 for 4087 independent reflections with I > 2σ(I)
and wR2 = 0.1558 for all 4309 independent reflections.
All calculations were performed using SHELXTL
PLUS software package [6]. The complete set of crys-
tallographic data for compound II (coordinates of
atoms, bond lengths, bond angles, and anisotropic tem-
perature parameters) was deposited to the Cambridge
Crystallographic Data Centre (entry no. CCDC
755395).
1
Betulin 3,28-bis-O-trifluoroacetate (II). Trifluoro-
acetic anhydride, 20.2 ml (0.145 mol), was added
dropwise under stirring to a suspension of 4.0 g
(9 mmol) of betulin (I) in 35 ml of carbon tetra-
chloride, maintaining the temperature of the reaction
mixture in the range from 0 to 10°C. When the addi-
tion was complete, the mixture was stirred for 15 min
at room temperature, and the solvent, excess trifluoro-
acetic anhydride, and trifluoroacetic acid formed
during the process were distilled off under reduced
pressure (12 mm) at a bath temperature not exceeding
40°C. To ensure complete removal of trifluoroacetic
anhydride and trifluoroacetic acid, 2×5 ml of carbon
tetrachloride was added to the distillation flask. The
residue was compound II as a light brown substance.
Recrystallization from ethyl acetate gave colorless
Hydrolysis of betulin 3,28-bis-O-trifluoroacetate
(II). A solution of 0.101 g (2.5 mmol) of sodium
hydroxide in 0.3 ml of ethanol was added to a solution
of 0.503 g (0.78 mmol) of betulin 3,28-bis-O-trifluoro-
acetate (II) in 5 ml of toluene, and the mixture was
heated for 3 h at 60°C. Water, 10 ml, was then added,
and the colorless precipitate was filtered off, washed
with water, and dried. Yield of betulin (I) 0.33 g
(94%), mp 254–256°C.
crystals. Yield 5.1 g (89%), mp 183–185°C, [α]D20
=
+4.3° (c = 0.015, CHCl3). IR spectrum, ν, cm–1: 1792
REFERENCES
1
(C=O), 1640 (C=C), 1220 (C–F). H NMR spectrum,
δ, ppm: 0.80 s, 0.88 s, 0.89 s, 0.98 s, and 1.05 s (15H,
1. Tolstikov, G.A., Flekhter, O.B., Shul’ts, E.E., Balti-
na, L.A., and Tolstikov, A.G., Khim. Inter. Ustoich. Razv.,
2005, vol. 13, p. 1.
2. Ashavina, O.Yu., Flekhter, O.B., Galin, F.Z., Kabal’no-
va, N.N., Baltina, L.A., and Tolstikov, G.A., Khim.
Prirod. Soedin., 2003, no. 2, p. 156.
3. Ietidal Eltahir, M., Iqbal, Ch., Shamsher, A., Shazia, A.,
and Atta-ur-Rahman, Acta Crystallogr., Sect. E, 2006,
vol. 62, p. o1352.
4. Roshchin, V.I., Shabanova, N.Yu., and Vedernikov, D.N.,
Russian Patent no. 2184120, 2002; Byull. Izobret., 2002,
no. 18.
CH3), 1.20–2.40 m (26H, CH2, CH), 1.69 s (3H, 30-H),
3
2.43 d (1H, 19-H, J = 6.6 Hz), 4.67 d.d (1H, 3-H, J =
2
11.0, 4.4 Hz), 4.13 d and 4.56 d (1H each, 28-H, J =
11.0 Hz), 4.70 s and 4.62 s (1H each, 29-H). 19F NMR
spectrum, δF, ppm: –76.08 s and –76.49 s (CF3).
Found, %: C 64.17; H 7.52. C34H48F6O4. Calculated,
%: C 64.34; H 7.62.
Crystallographic data for betulin 3,28-bis-O-tri-
fluoroacetate (II): C34H48F6O4, M 634.75; 0.30×0.25×
0.20 mm; monoclinic crystal system, space group P21.
Unit cell parameters (at 100 K): a = 9.5242(4), b =
14.6638(8), c = 11.7096(8) Å; β = 105.314(5)°; V =
5. Flekhter, O.B., Karachurina, L.T., Poroikov, L.R., Nigma-
tullina, L.R., Baltina, L.A., Zarudii, F.S., Davydova, V.A.,
Spirikhin, L.V., Baikova, I.P., Galin, F.Z., and Tolsti-
kov, G.A., Bioorg. Khim., 2000, vol. 26, no. 3, p. 215.
1577.31(16) Å3; Z = 2 (Z′ = 1); F(000) = 678; dcalc
=
1.339 g/cm3; μ = 0.109 mm–1. The unit cell parameters
and intensities of 19104 reflections were measured on
a Smart Apex2 CCD diffractometer at 100 K (MoKα
6. Sheldrick, G.M., SHELXTL-97, Version 5.10, Madison,
WI, USA: Bruker AXS.
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 46 No. 10 2010