2,3-BUTADIENOIC ACID,2-ETHYL,METHYL ESTER 2,3-butadienoic acid, 2-ethyl-, methyl ester InChI=1/C7H10O2/c1-4-6(5-2)7(8)9-3/h1,5H2,2-3H methyl 2-ethylbuta-2,3-dienoate