(2S,3R,4E,6E)-1,2-O-isopropylidene-8-tert-butyldimethylsilyloxy-1,2-dihydroxy-4,6-octadiene-3-yl propynoate

(2S,3S,4E,6E)-1,2-O-isopropylidene-8-tert-butyldimethylsilyloxy-1,2-dihydroxy-4,6-octadien-3-yl hydrogen (2Z)-2-butenedioate