Synonyms: PDII;Bis[(Z)-2-methyl-2-butenoic acid](9S,10S)-2-oxo-8,8-dimethyl-9,10-dihydro-2H,8H-benzo[1,2-b:3,4-b']dipyran-9β,10β-diyl ester;Bis[(Z)-2-methyl-2-butenoic acid][(9S,10S)-9,10-dihydro-8,8-dimethyl-2-oxo-2H,8H-benzo[1,2-b:3,4-b']dipyran]-9,10-diyl ester