名称:
Synthesis of (±)-2′,3′-didehydro-2′,3′-dideoxy nucleosides via a modified Prins reaction and palladium(0) catalysed coupling
摘要:
Cyclopentenyl allylic acetates have been prepared in diastereoisomerically enriched form by modification of the Prins reaction. Palladium(o) catalysed coupling between these allylic acetates and a heteroaromatic base provides a highly convergent and direct route for synthesising carbocyclic 2',3'-didehydro-2',3'-dideoxy nucleosides. The method is exemplified by the coupling reaction with adenine which yields (+/-)-2',3'-didehydro-2',3'-dideoxyaristeromycin 5'-O-acetate 22 in 50% yield. This has been converted in two steps into (+/-)-aristeromycin triacetate 5.