Stereoselective synthesis of conformationally rigid apio carbanucleosides as potential antiviral agents.

Apio north-methanocarbocyclic nucleosides 1-3 with bicyclo[3. 1.0]hexane template were first synthesized. Introduction of hydroxymethyl substituent was efficiently and stereoselectively accomplished by aldol and retro-aldol reaction and fixed conformation was achieved from a modified Simmons-Smith cyclopropanation on a cyclopentane ring.