methyl 1,2,4,6,6a,7,8,9-octahydro-2-methoxy-8,8-dimethylpentaleno<1,6a-c>pyran-5-carboxylate

tetrahydro-5',5'-dimethyl-3'-methylenespiro<1,3-dioxolane-2,2'(1'H)-pentalene>-3'a(3'H)-acetaldehyde

((3aR,6aS)-2,2-Dimethyl-4-methylene-5-oxo-hexahydro-pentalen-3a-yl)-acetaldehyde

hexahydro-8,8-dimethylpentaleno<1,6a-c>pyran-2,5(1H,6H)-dione

(2S,4aS,6aS,9aR)-octahydro-2-methoxy-8,8-dimethylpentaleno<1,6a-c>pyran-5(6H)-one