Facile Synthesis of Enantiomerically Pure Carbafuranoses: Precursors of Carbocyclic Nucleosides

Abstract

An efficient and highly diastereoselective synthetic approach to enantiomerically pure (−)-(1R,2R,3S,4R)- and (+)-(1S,2S,3R,4S)-4-hydroxyethylcyclopentane-1,2,3-triols is reported, which involves conversion of D-ribose or D-arabinose to (+)- or (−)-ethyl Z-4,5-isopropylidenedioxyhepta-2,6-dienoate, mercuration of the terminal double bond by mercury(II) acetate, followed by reductive radical cyclization and further standard reduction and deprotection manipulations.