USE OF A CYCLIC SULFITE AS AN EPOXIDE SURROGATE IN THE REGIOSELECTIVESYNTHESIS OF A CARBOCYCLIC RING-ENLARGED 4',1'A-METHANO OXETANOCIN ANALOG

Although cyclic sulfites are less reactive than their cyclic sulfate c ounterparts, the present work shows that cyclic sulfite 15a is a usefu l synthon for the convergent synthesis of carbocyclic nucleosides. Tar get compound 6, which represents a rigid carbocyclic nucleoside mimic of anti-HIV active 9-[2',3'-dideoxy-3'-C- hydroxymethyl)-beta-erythro- pentofuranosyl]adenine (3), was obtained after regioselective ring ope ning of 15a with adenine and radical-induced deoxygenation of the extr a hydroxyl group.