Asymmetric synthesis of L-cyclopentyl carbocyclic nucleosides

Abstract

Asymmetric synthesis of L-carbocyclic nucleosides, (+)-β-L-aristeromycin ( 11) and its thymine analog ( 12) was accomplished. The key intermediate 3 was synthesized by a regioselective conjugate addition to the enone 1 followed by DIBAL-H reduction. Coupling of 4 with heterocycle or construction of heterocyle by a linear approach gave 11 and 12. This is the first asymmetric synthesis of L-cyclopentyl carbocyclic nucleosides.