(3a'S,4S,5'R,8'S,9'S,9a'S,10'R)-10'-allyl-2,2,2',2'-tetramethyl-7'-oxotetrahydro-5'H,7'H-spiro[[1,3]dioxolane-4,4'-[5,9]methano[1,3]dioxolo[4,5-d]oxocin]-8'-yl pivalate

(S)-1-((3aS,4S,5R,6R,7S,7aS)-6-allyl-5-hydroxy-2,2,2',2'-tetramethyltetrahydro-5H-spiro[benzo[d][1,3]dioxole-4,4'-[1,3]dioxolan]-7-yl)-2-(dimethylamino)-2-oxoethyl pivalate