Process for producing 4,4,4,-trifluoro-3-hydroxybutyric acid

A process for producing an optically active 4,4,4-trifluoro-3-hydroxybutyric acid aryl ester derivative represented by the formula:

• said process comprising oxidizing an optically active 4,4,4-trifluoro-3-hydroxy-1-aryl-1-butanone derivative represented by the formula:
• thereby achieving Baeyer-Villiger oxidation and producing said aryl ester derivative,
• where X is a hydrogen, a C1-6 alkyl, a C1-6 alkoxy, or a halogen atom selected from the group consisting of F, Cl, Br and I;
• and the symbol * represents an asymmetric carbon.

A process for producing an optically active 4,4,4-trifluoro-1,3-butanediol represented by the formula:

• said process comprising:
• oxidizing an optically active 4,4,4-trifluoro-3-hydroxy-1-aryl-1-butanone derivative represented by the formula:
• thereby achieving Baeyer-Villiger oxidation and producing an optically active 4,4,4-trifluoro-3-hydroxybutyric acid aryl ester derivative represented by the formula:
• and
• reducing said aryl ester derivative by a hydride, thereby producing said butanediol,
• where the symbol * represents an asymmetric carbon, and X is a hydrogen, a C1-6 alkyl, a C1-6 alkoxy, or a halogen atom selected from the group consisting of F, Cl, Br and I.

A process for producing an optically active 4,4,4 trifluoro-3-hydroxybutyric acid alkyl ester derivative represented by the formula:

• said process comprising:
• oxidizing an optically active 4,4,4-trifluoro-3-hydroxy-1-aryl-1-butanone derivative represented by the formula:
• thereby achieving Baeyer-Villiger oxidation and producing an optically active 4,4,4-trifluoro-3-hydroxybutyric acid aryl ester derivative represented by the formula:
• and
• reacting under an acid condition said aryl ester derivative with a lower alcohol represented by the general formula ROH, thereby achieving an ester exchange and producing said alkyl ester derivative, where R is a C1-6 alkyl;
• the symbol * represents an asymmetric carbon, and X is a hydrogen, a C1-6 alkyl, a C1-6 alkoxy, or a halogen atom selected from the group consisting of F, Cl, Br and I.