A short and efficient transformation of rhamnose into activated daunosamine, acosamine, ristosamine and epi-daunosamine derivatives, and synthesis of an anthracycline antibiotic acosaminyl-ε-iso-rhodomycinone
constituents of most anthracycline antitumour antibiotics. For an investigation of structure-activity relationships, the four diastereomeric amino sugars daunosamine, acosamine, ristosamine, and epi-daunosamine were synthesised in short and efficient routes starting from commercially available rhamnose. Several glycosyl donors were provided and their use was exemplified in the synthesis of acosaminyl-e
A simple method has been developed for synthesizing previously unknown 2-C-acyl glycals. Direct Friedel-Crafts acylation of glycals with acetyl chloride or acetic anhydride in the presence of AlCl3 or FeCl3 gave 2-C-acetyl-hex-1-enitols in yields often better than 80%-90%. Interestingly, the 2-C-acetyl-hex-1-enitols can also be prepared in a single step from 1-O-acetyl-and 1-O-silyl-2-deoxy-hexopyranoses, and for all reactions excellent yields were observed.
KOLAR, CENEK;DEHMEL, KONRAD;MOLDENHAUER, HANS;GEREN, MANFRED, J. CARBOHYDR. CHEM., 9,(1990) N, C. 873-890