Divergent synthesis of two precursors of 3′-homo-2′-deoxy- and 2′-homo-3′-deoxy-carbocyclic nucleosides

Aminocyclopentanedimethanols and , which are of interest for the synthesis of higher homologues of 2′-deoxy- and 3′-deoxycarbonucleosides, respectively, were efficiently prepared by divergent routes starting from (±)-exo-bicyclo[2.2.1]hept-5-ene-2-carbaldehyde. In the key step, ammonolysis of the common intermediate (±)-(1β,3β,4α)-4-benzoyloxymethyl-1,3-cyclopentanedicarboxylic anhydride and subsequent esterification afford near-equimolar amounts of two easily separable isomeric carbamoyl esters.