作者:Michael Plewe、Konrad Sandhoff、Richard R. Schmidt
DOI:10.1016/0008-6215(92)80085-f
日期:1992.11
Benzyl 2,3,6-tri-O-benzyl-4-deoxy-4-C-methylene-alpha-D-xylo-hexopyranoside (3) was transformed with 3-chloroperoxybenzoic acid into the epoxides 4 and 5. Reductive opening of the epoxide moiety in 4 furnished benzyl 2,3,6-tri-O-benzyl-4-C-methyl-alpha-D-glucopyranoside (6); subsequent hydrogenolytic O-debenzylation, per-O-acetylation, selective removal of the anomeric O-acetyl group, and then treatment with trichloroacetonitrile in the presence of base afforded 2,3,4,6-tetra-O-acetyl-4-C-methyl-D-glucopyranosyl trichloroacetimidate (9). Reaction of 9 with the 3-O-benzoyl-azidosphingosines 10a,b in the presence of BF3 . OEt2 gave (2S,3R,4E)-2-azido-3-benzoyloxy-1-(2,3,4,6-tetra-O-acetyl-4-C-methyl-beta-D-glucopyranosyloxy)-4-octadecene (14a) and -4-dodecene (14b), respectively. Treatment of 14a,b with triphenylphosphine and the carboxylic acid anhydride in the presence of water and then with methanolic sodium methoxide gave the title compounds 16a,b.