Synthesis of carbovir and abacavir from a carbocyclic precursor.

A facile method for the synthesis of a carbocyclic analog of 2',3'-didehydro-2',3'-dideoxy-2-amino-6-chloropurine is presented, starting from the versatile lactam, 2-azabicyclo[2.2.1]hept-5-en-3-one. The corresponding anti-HIV nucleoside analogs, carbovir and its derivative abacavir, are prepared directly from the 6-chloro intermediate in one-step reactions.