The present invention pertains to a process for preparing 3-hydroxy-3-methylbutyrate (HMB) or a salt thereof, the method comprising (a) reacting isobutylene oxide with cyanide in order to obtain 3-hydroxy-3-methylbutyronitrile, and (b) hydrolyzing the 3-hydroxy-3-methylbutyronitrile obtained in step (a) in order to obtain HMB, wherein hydrolysis step (b) is performed using either at least one nitrilase enzyme or, alternatively, using a combination of enzymes, said combination comprising at least one nitrile hydratase and at least one amidase.

The present invention pertains to a process for preparing 3-hydroxy-3-methylbutyrate (HMB) or a salt thereof, the method comprising (a) reacting isobutylene oxide with cyanide in order to obtain 3-hydroxy-3-methylbutyronitrile, and (b) hydrolyzing the 3-hydroxy-3-methylbutyronitrile obtained in step (a) in order to obtain HMB, wherein hydrolysis step (b) is performed using either at least one nitrilase enzyme or, alternatively, using a combination of enzymes, said combination comprising at least one nitrile hydratase and at least one amidase.

Provided is a preparation method for brivaracetam. The method has a synthetic route as shown below. The preparation method for the brivaracetam is simple, economical, environmentally friendly and suitable for industrialization:

##STR00001##

Provided is a preparation method for brivaracetam. The method has a synthetic route as shown below. The preparation method for the brivaracetam is simple, economical, environmentally friendly and suitable for industrialization:

##STR00001##

The present invention discloses a process for preparing optically pure (R)-4-n-propyl-dihydrofuran-2(3H)-one, belonging to the field of chemical synthesis. According to the process, optically pure (S)-3-n-pentanoyl-4-substituted oxazol-2-one is used as a starting material, and after alkylation, reduction, cyano hydrolysis, lactonization, the product optically pure (R)-4-n-propyl-dihydrofuran-2(3H)-one is given. The preparation process has the advantages of easy availability of raw materials, low price, high yield, high optical purity of product, simple reaction conditions and simple operations.

The present invention discloses a process for preparing optically pure (R)-4-n-propyl-dihydrofuran-2(3H)-one, belonging to the field of chemical synthesis. According to the process, optically pure (S)-3-n-pentanoyl-4-substituted oxazol-2-one is used as a starting material, and after alkylation, reduction, cyano hydrolysis, lactonization, the product optically pure (R)-4-n-propyl-dihydrofuran-2(3H)-one is given. The preparation process has the advantages of easy availability of raw materials, low price, high yield, high optical purity of product, simple reaction conditions and simple operations.

The present invention provides an agent for the prophylactic or treatment of diabetes, diabetic complications, insulin resistance syndrome, metabolic syndrome, hyperglycemia, dyslipidemia, atherosclerosis, cardiac failure, cardiomyopathy, myocardial ischemia, brain ischemia, cerebral apoplexy, pulmonary hypertension, hyperlactacidemia, mitochondrial disease, mitochondrial encephalomyopathy or cancer, namely, a PDHK inhibitor and the like. A compound represented by the following formula [I] or a pharmaceutically acceptable salt thereof, or a solvate thereof:

##STR00001##

wherein each symbol is as defined in the specification.

The present invention provides an agent for the prophylactic or treatment of diabetes, diabetic complications, insulin resistance syndrome, metabolic syndrome, hyperglycemia, dyslipidemia, atherosclerosis, cardiac failure, cardiomyopathy, myocardial ischemia, brain ischemia, cerebral apoplexy, pulmonary hypertension, hyperlactacidemia, mitochondrial disease, mitochondrial encephalomyopathy or cancer, namely, a PDHK inhibitor and the like. A compound represented by the following formula [I] or a pharmaceutically acceptable salt thereof, or a solvate thereof:

##STR00001##

wherein each symbol is as defined in the specification.

The present invention provides a method for producing a diol having a specific structure in high yields while keeping high selectivity. Provided is a method for producing a diol having a specific structure by oxidizing an olefin having a specific structure in the presence of a ruthenium compound.

The present invention provides a method for producing a diol having a specific structure in high yields while keeping high selectivity. Provided is a method for producing a diol having a specific structure by oxidizing an olefin having a specific structure in the presence of a ruthenium compound.