Synthesis of sterically hindered 5'-esters of 6-chloro-9-(2,3-dideoxy-β-D-glycero-pentofuranosyl)purine as anti-HIV agents

The purpose of this research was to synthesize sterically hindered 5'-esters of 6-chloro-9-(2,3-dideoxy-β-D-glycero-pentofuranosyl)purine as a prodrug of the anti-HIV drug ddl, expecting to show resistance to intestinal ADA and intestinal esterase enzymes and consequently higher oral bioavailability.