(E)-3-methyl-4-oxo-2-butenoic acid

甲醇

维生素A丙酸酯

6-methyl-8t-(2,6,6-trimethyl-cyclohex-1-enyl)-octa-3t,5t,7-trien-2-one semicarbazone

(2E,4E)-3-methyl-5-(2,6,6-trimethylcyclohex-1-enyl)penta-2,4-dienoic acid