methyl (R)-6-methyl-2-((1R,7aR)-7a-methyl-1,2,3,6,7,7a-hexahydrospiro[indene-5,2'-[1,3]dioxolan]-1-yl)heptanoate

(1R,5R,6R)-methyl 2-oxo-6-methylbicyclo[3.1.0]hexane-1-carboxylate