An asymmetric transformation method of enriching a desired isomer of a substituted 2-trifluoromethyl-2 H -chromene-3-carboxylic acid, which is characterized by comprising: (a) in a solvent or mixture of solvents, contacting the substituted 2-trifluoromethyl-2 H- chromene-3-carboxylic acid with a chiral amine to form salts, wherein the chiral amine is selected so that the solubility of the amine salt of the undesired substituted 2-trifluoromethyl-2 H -chromene-3-carboxylic acid is greater than the amine salt of the desired substituted 2-trifluoromethyl-2 H -chromene-3-carboxylic acid, (b) irradiating the transformation mixture with an ultraviolet light, wherein the irradiation increases the amount of the less soluble chiral amine salt of the substituted of the 2-trifluoromethyl-2 H -chromene-3-carboxylic acid in the transformation mixture, (c) maintaining the irradiation for a period of time effective to increase the amount of the desired chiral amine salt of the substituted 2-trifluoromethyl-2 H -chromene-3-carboxylic acid isomer, (d) separating the desired chiral amine salt of the substituted 2-trifluoromethyl-2H-chromene-3-carboxylic acid by filtration of the precipitation, and (e) liberating the free form of the desired chiral substituted-2-trifluoromethyl-2H-chromen-3-carboxylic acid from the chiral amine salt by treatment with an acid, wherein the chiral amine is selected from the group consisting of: - N -Benzyl-alpha-methylbenzylamine, (1 R,2 R)-2-Amino-1-phenyl-1,3-propanediol, -1-(1-Naphthyl)ethylamine, -2-Amino-3-phenyl-1-propanol and L-Phenylalaninamide, wherein the solvent is selected from the group consisting of: hexane, heptane, cyclohexane, toluene, methanol, ethanol, 2-propanol, diisopropyl ether, tert -butyl methyl ether, tetrahydrofuran, 2-methyltetrahydrofuran, dioxane, acetone, methyl ethyl ketone, ethyl acetate, dichloromethane, acetonitrile, N,N -dimethylformamide, N- methylpyrrolidone, dimethyl sulfoxide, water, and a mixture of two or more thereof and wherein the substituted 2-trifluoromethyl-2 H -chromene-3-carboxylic acid is selected from the group consisting of the following compounds: 6-chloro-7- tert -butyl-2-trifluoromethyl-2 H -chromene-3-carboxylic acid, and 6,8-dichloro-2-trifluoromethyl-2 H -chromene-3-carboxylic acid. (a) in a solvent or mixture of solvents, contacting the substituted 2-trifluoromethyl-2 H- chromene-3-carboxylic acid with a chiral amine to form salts, wherein the chiral amine is selected so that the solubility of the amine salt of the undesired substituted 2-trifluoromethyl-2 H -chromene-3-carboxylic acid is greater than the amine salt of the desired substituted 2-trifluoromethyl-2 H -chromene-3-carboxylic acid, (b) irradiating the transformation mixture with an ultraviolet light, wherein the irradiation increases the amount of the less soluble chiral amine salt of the substituted of the 2-trifluoromethyl-2 H -chromene-3-carboxylic acid in the transformation mixture, (c) maintaining the irradiation for a period of time effective to increase the amount of the desired chiral amine salt of the substituted 2-trifluoromethyl-2 H -chromene-3-carboxylic acid isomer, (d) separating the desired chiral amine salt of the substituted 2-trifluoromethyl-2H-chromene-3-carboxylic acid by filtration of the precipitation, and (e) liberating the free form of the desired chiral substituted-2-trifluoromethyl-2H-chromen-3-carboxylic acid from the chiral amine salt by treatment with an acid, wherein the chiral amine is selected from the group consisting of: - N -Benzyl-alpha-methylbenzylamine, (1 R,2 R)-2-Amino-1-phenyl-1,3-propanediol, -1-(1-Naphthyl)ethylamine, -2-Amino-3-phenyl-1-propanol and L-Phenylalaninamide, wherein the solvent is selected from the group consisting of: hexane, heptane, cyclohexane, toluene, methanol, ethanol, 2-propanol, diisopropyl ether, tert -butyl methyl ether, tetrahydrofuran, 2-methyltetrahydrofuran, dioxane, acetone, methyl ethyl ketone, ethyl acetate, dichloromethane, acetonitrile, N,N -dimethylformamide, N- methylpyrrolidone, dimethyl sulfoxide, water, and a mixture of two or more thereof and wherein the substituted 2-trifluoromethyl-2 H -chromene-3-carboxylic acid is selected from the group consisting of the following compounds: 6-chloro-7- tert -butyl-2-trifluoromethyl-2 H -chromene-3-carboxylic acid, and 6,8-dichloro-2-trifluoromethyl-2 H -chromene-3-carboxylic acid. 6-chloro-7- tert -butyl-2-trifluoromethyl-2 H -chromene-3-carboxylic acid, and 6,8-dichloro-2-trifluoromethyl-2 H -chromene-3-carboxylic acid.