Potential use of carbocyclic nucleosides for the treatment of AIDS: chemo-enzymatic syntheses of the enantiomers of carbovir

Abstract

The lactam (1R),(4S)-2-azabicyclo[2.2.1]hept-5-en-3-one [(–)-2], derived by whole cell enantio-specific hydrolysis of the racemate was converted into (–)-carbovir (–)-1 in ten steps. Lipase catalysed acetylation of 4-cis-hydroxycyclopent-2-enylmethyl triphenylmethyl ether afforded the optically pure ester (+)-3 and the alcohol (–)-9. The former compound was converted into (+)-carbovir (+)-1 in three steps.