(S)-2-(dimethylamino)-2-oxo-1-((3aS,4R,7S,7aS)-2,2,2',2'-tetramethyl-6-methylene-5-oxotetrahydro-5H-spiro[benzo[d][1,3]dioxole-4,4'-[1,3]dioxolan]-7-yl)ethyl pivalate

(3a'S,4S,5'R,8'S,9'S,9a'S,10'R)-10'-(2-hydroxyethyl)-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 carbamate

(3a'S,4S,5'R,8'S,9'S,9a'S,10'R)-9'-amino-8'-hydroxy-2,2,2',2'-tetramethyl-10'-vinyltetrahydro-5'H,7'H-spiro[[1,3]dioxolane-4,4'-[5,9]methano[1,3]dioxolo[4,5-d]oxocin]-7'-one

(4S,6R,7S,7aS)-7-((tert-butyldimethylsilyl)oxy)-4-hydroxy-2',2'-dimethyl-2-oxo-4,5,7,7a-tetrahydro-2H-spiro[benzofuran-6,4'-[1,3]dioxolan]-3-yl pivalate