(1R,2R,3S,4S,5R)-1-O-mesyl-2-O-benzyl-3,4-O-isopropylidene-5-acetoxymethyl-cyclopentane-1,2,3,4-tetrol

(1R,5R,8R)-8-benzyloxy-2-oxabicyclo[3.3.0]oct-6-en-3-one

(1R,5R,8R)-8-Hydroxy-2-oxabicyclo[3.3.0]oct-6-en-3-one