2-Butenoic acid, 2-methyl-, (3S)-3,4-dihydro-5-hydroxy-2,2,8-trimethyl-6-oxo-2H,6H-benzo[1,2-b:5,4-b']dipyran-3-yl ester, (2Z)-

2-Butenoic acid, 2-methyl-, (3S)-3,4-dihydro-5-hydroxy-2,2,8-trimethyl-6-oxo-2H,6H-benzo[1,2-b:5,4-b']dipyran-3-yl ester, (2Z)- ·