| 摘要 |
A process for the synthesis of 1-O-steroidal-peracyl-.beta.-glycosides that provides greater .beta.-anomeric selectivity with reduced by-products and side reactions. The process comprises reacting heptaacyl-D-cellobiosyl-1-halide, tetraacyl-D-glucosyl-1-halide or tetraacyl-D-galactosyl-1-halide and a trisubstituted silyl-3-O-steroid, wherein the steroid is tigogenin, hecogenin, 11-ketotigogen-in, diosgenin, or cholesterol, in the presence of zinc fluoride under suitable conditions. Typically, the halide is bromide, chloride or fluoride, the acyl is alkanoyl(C1-C6), benzoyl or toluoyl and the silyl substitution is alkyl(C1-C6), phenyl or phenyl alkyl(C1-C6).
|
