Reaction Hydrosilylation of Allyl-2,3,5,6-Di-O-Isopropylidene-D-Mannofuranose with Methyl- and Phenylcyclodisilazanes

Byhydrosilylationof1-O-allyl-2,3;5,6-di-0-isopropylidene-D-mannofuranose (1) with 1,3-bis(dimethylsilyl)–2,2,4,4-tetra-methylcyclodisilazane (2) and 1,3-bis(diphenylsilyl)–2,2,4,4-tetra-phenylcyclodisilazane (3) in the presence of the catalyst Co₂(CO)₈, we obtained 1,3-di[3-(2,3;5,6-di–0-isopropylidene-D-mannofuranosyloxy)propyldimethylsilyl]–2,2,4,4-tetramethylcyclodisila-zane (4) and 1,3-di[3-(2,3;5,6-di-0-isopropylidene-D-mannofuranosyloxy) propyldiphenylsilyl]–2,2,4,4-tetra-phenylcyclodisilazane (5). After removal ofisopropylidene protections, we obtained 1,3-di[3-(β-D-mannofuranosyloxy) propyldimethylsilyl]–2,2,4,4-tetramethylcyclodisilazane (6) and 1,3-di[3-(β-D-mannofuranosyloxy)propyldiphenylsilyl]–2,2,4,4-tetraphenylcyclodisila-zane (7). The reaction mainly occurs according to Farmer’s rule, although a small amount of Markovnikov addition product is also formed.