SYNTHESIS OF TRITERPENE AND STEROID GLYCOSIDES

Article abstract of DOI:10.1016/S0008-6215(00)85361-6

The glycosylation of cholesterol, β-sitosterol, 28-O-acetylbetulin, and betulin with acylated glycosyl halides in the presence of Hg(OAc)2, Hg(CN)2, CdCO3, Ag2O, Ag2CO3, and HgO + HgBr2 usually gives acylated αβ-glycosides accompanied by acetates, ethers, and bromo and unsaturated derivatives of the initial alcohols.The use of Hg(CN)2 gave mainly β anomers (40-87percent), whereas α anomers preponderated when Hg(OAc)2 was the catalyst.When there was a deficiency of hydrogen halide acceptor and in the presence of the acidic catalyst HgBr2*HBr, the β anomer, produced initially, underwent anomerisation.Cholesteryl α-D-glucopyranoside tetra-acetate (48percent) was obtained by anomerisation of the β anomer.