methyl (E)-5-((3a'R,4'S,6'S,7'S,7a'R)-7'-acetoxy-4'-((S)-1,4-dioxaspiro[4.5]decan-2-yl)tetrahydro-4'H-spiro[cyclohexane-1,2'-[1,3]dioxolo[4,5-c]pyran]-6'-yl)pent-3-enoate