1,4,4-trimethyl-2-oxocyclopentane-1-carbaldehyde

ethyl 3-(1,4,4-trimethyl-2-oxocyclopentyl)prop-2-enoate

ethyl 3-(1',4',4'-trimethyl-2'-oxocyclopentyl)propanoate

ethyl 3-(6',8',8'-trimethyl-1',4'-dioxaspiro<4,4>non-6'-yl)propanoate

3-(7,7,9-trimethyl-1,4-dioxaspiro[4.4]nonan-9-yl)propan-1-ol