2-hydroxy-4,7-dimethyl-3,4-dihydro-2H,5H-pyrano[3,2-c]pyran-5-one

2-(4-hydroxy-6-methyl-2-oxo-2H-pyran-3-yl)-4,7-dimethyl-3,4-dihydro-2H,5H-pyrano[3,2-c]pyran-5-one

ethyl <1,3-bis(4-hydroxy-6-methyl-2-oxo-2H-pyran-3-yl)>butyl ether

4,4,7-trimethyl-2-(2-oxopropyl)pyrano[4,3-b]pyran-5-one

ethyl 3,5-dioxohexanoate