A new stereoselective route to the carbocyclic nucleoside cyclobut-A

Abstract

A new synthesis of cyclobut-A, a carbocyclic nucleoside analogue of oxetanocin is described. The key step involves a stereoselective intramolecular [2+2] photocycloaddition to provide a trisubstituted cyclobutane derivative with the desired stereochemistry. The nucleoside linkage was established through nucleophilic displacement of an acetate group by adenine.