142689-06-3 1H-2-Benzopyran-7-carboxylic acid, 3,4-dihydro-6,8-dihydroxy-3,4-dimethyl-5-fluoro- 3,4-Dihydro-6,8-dihydroxy-3,4-dimethyl-5-fluoro-1H-2-benzopyran-7-carboxylic acid