The first synthesis of a 2′,3′-methano carbocyclic nucleoside

A 2′,3′-methano carbocyclic nucleoside, 9-( c-4-hydroxymethylbicyclo[3.1.0]hex- r-2-yl)-9 H-adenine, has been efficiently synthesized from 2-azabicyclo[2.2.1]hex-5-en-3-one(ABH) in six steps involving 1,3-dipolar cycloaddition, photolysis, and adenine ring construction.