5,6-dimethyl-3-(2-methylprop-1-en-1-yl)cyclohex-4-ene-1,2-dicarboxylic anhydride
(+/-)-3t,4-dimethyl-6c-(2-methyl-propenyl)-cyclohex-4-ene-1r,2c-dicarboxylic acid-anhydride
(+/-)-3c.4-dimethyl-6c-(2-methyl-propenyl)-cyclohexene-(4)-dicarboxylic acid-(1r.2c)
(+/-)-6c-isobutyl-3c,4ξ-dimethyl-cyclohexane-1r,2c-dicarboxylic acid-anhydride