methyl 2-((3a'R,4'S,5a'S,8'R,9a'S,9b'S)-4'-((S,E)-1-hydroxy-3-(trimethylsilyl)allyl)octahydrospiro[cyclohexane-1,2'-[1,3]dioxolo[4,5-d]pyrano[3,2-b]pyran]-8'-yl)acetate