A rapid access to carbocyclic nucleosides containing a fused isoxazoline ring is proposed starting from cyclopentadiene. The route involves an hetero Diels–Alder cycloaddition reaction of nitrosocarbonylbenzene followed by a 1, 3-dipolar cycloaddition of nitrile oxides, cleavage of the N–O tether and elaboration of the heterocyclic aminols into nucleosides via linear construction of purine and pyrimidine heterocycles.
