4-methyl-1-oxoisochromene-3-carboxylic acid

(9ci)-1H-2-苯并吡喃-1,4(3h)-二酮

2-[3-(2-methoxyphenyl)prop-2-enoyl]benzoic acid

1-methyl-2-benzofuran

2-(2-acetylphenyl)-4H-1,3-oxazol-5-one