3-hydroxy-2-methyl-7-[(1E)-prop-1-en-1-yl]-2,3-dihydro-4H,5H-pyrano[4,3-b]pyran-4,5-dione 4H,5H-pyrano[4,3-b]pyran-4,5-dione, 2,3-dihydro-3-hydroxy-2-methyl-7-[(1E)-1-propenyl]- InChI=1/C12H12O5/c1-3-4-7-5-8-9(12(15)17-7)11(14)10(13)6(2)16-8/h3-6,10,13H,1-2H3/b4-3