Enantiospecific syntheses of aristeromycin and neplanocin A

The carbocyclic nucleosides (−)-aristeromycin and (−)-neplanocin A were made enantiospecifically in nine steps and ten steps, respectively, from D-ribonic acid γ-lactone. Quenching of an organocuprate conjugate addition reaction with either acetic acid or methanesulfinyl chloride determines whether the divergent synthetic route branches toward (−)-aristeromycin or (−)-neplanocin A