6-hydroxy-5,7,8-trimethyl-3,4-dihydrochromen-2-one

2-bromo-3-fluoropropanoic acid

2-甲基-6-氧代-1,4,5,6-四氢吡啶-3-羧酸乙酯

5-butyl-4,5-dihydro-3-methylene-2(3H)-furanone

2-butyl-4-methyl-2H-furan-5-one