(4R,5S,6R)-6,7-epoxy-4,5-dibenzyloxy-1-pivaloyloxy-2-heptene

(2R,3R,4R)-3,4-dibenzyloxy-7-pivaloyloxy-5-heptene-1,2-diol

(4R,5R,6R)-4,5-dibenzyloxy-6,7-isopropylidenedioxy-1-pivaloyloxy-2-heptene