3-((3R,3aS,6R,7aS)-3a-(3-((tert-butyldimethylsilyl)oxy)propyl)-6-methyl-2-oxooctahydrospiro[indene-4,2'-[1,3]dioxolan]-3-yl)propanal

(4bS,7R,8aS)-4b-(3-((tert-butyldimethylsilyl)oxy)propyl)-7-methyl-4b,6,7,8,8a,9-hexahydrospiro[indeno[2,1-b]pyridine-5,2'-[1,3]dioxolane]