Synthesis of chiral oxepinopyran and oxepinooxepane systems from 1,2-isopropylidene furanoside ring-fused cyclic ether derivatives through 4-O-allyl nitrone and nitrile oxide cycloadditions

A novel strategy was developed by which chiral oxepinopyran and oxepinooxepane derivatives were synthesised from 1,2-isopropylidene furanoside fused pyran and oxepane derivatives by the cycloaddition of 4-O-allyl nitrone or nitrile oxide species generated from the furanoside ring