(2Z)-[(5Z)-5-(2-methoxy-2-oxoethylidene)-2,2,3,3,4,4-hexamethylcyclopentylidene]acetic acid InChI=1/C16H24O4/c1-14(2)10(8-12(17)18)11(9-13(19)20-7)15(3,4)16(14,5)6/h8-9H,1-7H3,(H,17,18)/b10-8+,11-9 acetic acid, 2,2'-[(1Z)-3,3,4,4,5,5-hexamethyl-1,2-cyclopentanediylidene]bis-, methyl ester, (2Z,2'Z)-