Diastereoselective synthesis of a collection of new homonucleoside mimetics containing pyrrolo[1,2.b]isoxazoline and pyrrolidine rings

The 1,3-dipolar cycloaddition of enantiopure cyclic hydroxylated nitrones and allyl nucleobases has been exploited for the preparation of a novel class of homonucleoside mimetics, where the furanose ring is replaced by a pyrrolo[1,2-b]isoxazolidine system. The nitrones were easily prepared starting from L-malic and L-tartaric acids and gave cycloadducts in a diastereoselective manner, which were deprotected to give good yields of the homo-N,O-nucleoside mimetics. The reduction of the isoxazolidine ring, a 1,3- aminoalcohol equivalent, allows easy access to other new pyrrolidine nucleoside mimetics.