Spiro[cyclohexane-​1,​4'(3'H)​-​[1H-​7,​9a]​methanocyclohepta[c]​pyran]​-​2-​carboxaldehyde, hexahydro-​5'-​hydroxy-​3,​3-​dimethyl-​8'-​methylene-​1',​9'-​dioxo-​, (1R,​2R,​4'aS,​5'R,​7'S,​9'aS)​-