2-Butenoic acid, 2-methyl-, (Z)-, sumbulic acid, trans-2-methyl-2-butenoic acid, trans-2,3-dimethylacrylic acid, cis-2-Methyl-2-butenoic acid, 2-methyl-cis-crotonicacid, (Z)-MeCH=C(Me)COOH, (Z)-2-methyl-2-butenoic acid, ANGELIC ACID(RG), ANGELIC ACID, 2-METHYLISOCROTONIC ACID, cis-2-methylbutenoic acid