(1R*,3S*,5R*,6S*)-1-methyl-9-oxatricyclo<3.2.2.03,6>nonan-8-one

(1S,3S,5R)-6-Chloro-3,6-dimethyl-7-oxo-bicyclo[3.2.0]heptane-3-carboxylic acid

(2S,3aR,6aR)-4-Chloro-2,4-dimethyl-5-oxo-octahydro-pentalene-2-carboxylic acid methyl ester