| 摘要 |
<p>1,235,031. Steroid rhamnosides. DR. KARL THOMAE G.m.b.H. 5 May, 1969 [3 May, 1968], No. 22826/69. Heading C2U. [Also in Division A5] The invention comprises compounds of formula wherein R 1 is a group of structure A or B where each R 3 is H or -COR 4 ; R 4 is C 1-3 alkyl; and R 2 is H, C 1-3 alkyl, acyl, benzyl, tetrahydropyran-2-yl or -SO 3 M, where M is an alkali metal atom. Compounds I wherein R 2 is other than -SO 3 M and R 3 is -COR 4 are prepared by reacting the corresponding 17-ols with a trio - alkanoyl -α- L - rhamnopyranosyl halide to give a product comprising structure A and/or structure B. When a mixture is obtained it is separated by saponification of the alkanoyl groups and chromatography of the resulting deacyl mixture. Compounds I wherein R 2 is -SO 3 M and R 3 is H are prepared from compounds I wherein R 2 is H and R 3 is -COR 4 by reaction with sulphamic acid and treatment of the resulting 3-hemisulphate with an alkali. Other product interconversions described are esterification, saponification of ester groups, 3- etherification, and 3-debenzylation.</p> |
