Synthesis and transformations of (1R,2R,3S,4R)-4-O-benzylhydroxylamino-2,3-O-isopropylidene-1,2,3-cyclopentanetriol: synthesis of (1S,2R,3S,4R)-4-amino-2,3-O-isopropylidene-1,2,3-cyclopentanetriol