2-Aza-3-oxabicyclo[2.2.1]heptene hydrochloride: An exceptionally versatile synthon for carbocyclic sugars and nucleosides

Abstract

The transformation of cyclopentadiene to 5′-desmethylene 1′-aza carbocyclic sugars has been achieved in four steps: 1. Cycloaddition of chloronitrosocyclohexane to 2-aza-3-oxabicyclo[2.2.1]heptene hydrochloride in EtOH-Et 2O, 2. Nitrogen functiona-lization, 3. cis hydroxylation and 4. NO bond cleavage. The protocols provided enable practical access to a range of 5′-desmethylene carbocyclic sugar analogs whose utility has been illustrated with synthesis of a novel 5′-desmethylene analog of aristeromycin.