In our continuing study of the preparation and development of novel carbocyclic nucleosides as potential antiviral agents, we have been interested in 2^’, 3^’-methano-, azamethano- and oxamethano-carbocyclic nucleosides in which the cyclopentane ring was conformationally constrained by the fused three-membered rings.

The present review deals with the recent results concerning a novel approach to 2^’,3’-methano-carbocyclic nucleoside derivatives based on the use of 2-azabicyclo [2.2.1] hept-5-en-3-one(ABH)  as a versatile synthon.