55247-73-9 CROTONIC ACID, 3-METHYL-, ESTER with 2,3-DIHYDRO-2-(1-HYDROXY-1-METHYLETHYL)-7H- Crotonic acid, 3-methyl-, ester with 2,3-dihydro-2-(1-hydroxy-1-methylethyl)-7H-furo(3,2-g)(1)benzopyran-7-one, (-)-, mixed with N-vinylpyrrolidone (14:86)