Synthesis of 3-deoxy-3-nucleobase-2,5-anhydro-D-mannitol: a novel class ofhydroxymethyl-branched isonucleosides

A concise synthesis of 3-deoxy-3-nucleobase-2,5-anhydro-D-mannitol 6(a-d) h as been achieved, using the deamination of 2-amino-2-deoxy-D-glucose to con struct in one step the sugar skeleton with the desired sense of chirality a t each asymmetric center. The selective dibenzoylation of 2,5-anhydro-D-man nitol 9 was investigated, and the key epoxide intermediate 13 was obtained in good yield via an intramolecular Mitsunobu reaction. The process of open ing of epoxide 13 by nucleobases appeared to be regioselective. (C) 2000 El sevier Science Ltd. All rights reserved.