Synthesis of methylenecyclobutyl- and cyclobutenyl adenine A, potent antiviral carbocyclic analogues of oxetanocin A.

9-Cyclobutyladenines bearing both methylene and hydroxymethyl groups, 3 and 4, were prepared by dehydration of carbocyclic oxetanocin A, 1a. Introduction of a double bond into cyclobutane ring was achieved by allylic oxidation of 12, which after several steps, afforded 5.