Synthesis of 3'',4''-bisphosphate-containing analogs of adenophostin A

Glycosylation of ethyl 3,4,6-tri-O-acetyl-2-O-benzyl-1-thio-alpha/beta-D-glucopyranoside (6) with tert-butyldiphenylsilylglycol (7) or 1,2-di-O-p-methoxybenzyl-sn-glycerol (16) under the agency of N-iodosuccinimide/triflic acid afforded alpha-glucosides 8 and 17, respectively. Protective group manipulations (8 --> 10 and 17 --> 20) and acetolysis of the methylthiomethyl functions yielded 2-O-(3,4,6-tri-O-acetyl-2-O-benzyl-alpha-D-glucopyranosyl)-1-O-acetoxymethylglycol (11) and 3-O-(3,4,6-tri-O-acetyl-2-O-benzyl-alpha-D-glucopyranosyl)-2-O-acetoxymethyl-1-O-tert-butyldiphenylsilyl-sn-glycerol (21). Vorbruggen condensation with silylated 6-N-benzoyladenine (22), subsequent protective group manipulations on 23 and 29 followed by phosphorylation furnished, after purification, homogeneous glycol-based adenophostin A analog 4 and glycerol-based analog 5. (C) 1997 Elsevier Science Ltd.