吡喃是六元杂环，非芳香环，由五个碳原子和一个氧原子组成，并含有两个双键。分子式为C5H6O，吡喃有两个异构体，其位置与双键的位置不同。在2H吡喃中，饱和碳处于位置2，而在4H-吡喃中，饱和碳位于位置4。
5,7-Dimethoxy-2H-chromen-2-one
4-(Bromomethyl)-7-methoxy-2H-chromen-2-one
6,7-Dimethoxy-2H-chromen-2-one
6-Hydroxy-7-methoxy-2H-chromen-2-one
4-(Hydroxymethyl)-7-methoxy-2H-chromen-2-one
8-Bromochroman-4-one
8-Bromo-6-fluorochroman-4-one
6,8-Dibromochroman-4-one
8-Bromo-6-methyl-3,4-dihydro-2H-1-benzopyran-4-one
Ethyl 2-oxo-2H-chromene-3-carboxylate
Ethyl 7-(diethylamino)-2-oxo-2H-chromene-3-carboxylate
Ethyl 7-hydroxy-2-oxo-2H-chromene-3-carboxylate
Ethyl 6-bromo-2-oxo-2H-chromene-3-carboxylate
Ethyl 7-bromo-2-oxochromene-3-carboxylate
6-Chloro-8-(trifluoromethyl)chroman-4-one
6-Chloro-8-fluorochroman-4-one
6,8-Dichlorochroman-4-one
6-Chloro-8-methylchroman-4-one
6,7-Dichlorochroman-4-one
6-Chlorochroman-4-one
6-Bromo-2,2-dimethylchroman-4-one
6-Bromo-8-fluorochroman-4-one
6-Bromo-7-fluorochroman-4-one
6-Bromochroman-4-one
6-Bromo-7-methylchroman-4-one
6-Bromo-5-methylchroman-4-one
4-Chromanol
(R)-5,7-Difluorochroman-4-ol
6-Bromochroman-4-ol
5,7-Difluorochroman-4-ol
