CONCISE AND STEREOSPECIFIC SYNTHESIS OF NOVEL BICYCLIC DIDEOXYNUCLEOSIDES AS POTENTIAL ANTIVIRAL AGENTS

A novel class of dideoxynucleosides containing a bicyclic sugar moiety , structurally related to the natural griseolic acids, was synthesized starting from the stereochemically defined compound, 1,4:3,6-dianhydr o-D-glucitol. The key intermediate in the synthesis was a [3.3.0] fuse d bicyclic glycal. Glycosylation of this compound with nucleobase proc eeded both regiospecifically and stereospecifically in the presence of an auxiliary agent, N-iodosuccinamide. Changes in stereochemistry dur ing the synthesis was monitored by optical rotation data and confirmed by both 1D and 2D NMR experiments. The synthetic approach described p ossesses general usefulness. (C) 1998 Elsevier Science Ltd. All rights reserved.