A process for the preparation of Brivaracetam, an anti-convulsion drug, is provided comprising enzymatic conversion of (2RS)-2-[ (4R)-2-oxo-4-propyl-pyrrolidin-1-yl] butyric acid methyl ester selectively into (2S)-2-[ (4R)-2-oxo-4-propyl-pyrrolidin-1-yl] butyric acid having high chiral purity, using protease from Bacillus licheniformis. Converting the chirally pure acid into an amide results in Brivaracetam.

A process for the preparation of Brivaracetam, an anti-convulsion drug, is provided comprising enzymatic conversion of (2RS)-2-[(4R)-2-oxo-4-propyl-pyrrolidin-1-yl] butyric acid methyl ester selectively into (2S)-2-[(4R)-2-oxo-4-propyl-pyrrolidin-1-yl] butyric acid having high chiral purity, using protease from Bacillus licheniformis. Converting the chirally pure acid into amide results in Brivaracetam.

The present invention relates to a process for carbonylating allyl alcohols at low temperature, low pressure and/or low catalyst loading. In an alternative embodiment, an acylation product of the allyl alcohol is used for the carbonylation. The present invention likewise relates to the preparation of conversion products of these carbonylation products and specifically of (−)-ambrox.

The invention provides an improved method of isolating the 3-(E)-isomer of an unsaturated carboxylic acid from a mixture of corresponding (E/Z)isomers. More particularly, the present invention relates to an improved method for the biocatalytic preparation of (3E,7E)-homofarnesylic acid; as well as a novel biocatalytic method for the improved preparation of homofarnesol, in particular of (3E,7E)-homofarnesol and homofarnesol preparations having an increased content of (3E,7E)-homofarnesol. The present invention also relates to methods of preparing(−)-ambroxby applying (3E,7E)-homofarnesylic acid or (3E,7E)-homofarnesol as obtained according to the invention as starting material.

Methylopila sp. and use thereof in the selective resolution preparation of (S)-α-ethyl-2-oxo-1-pyrrolidineacetate. Methylopila sp. that produces enzymes is subjected to cell immobilization, and is then applied to the biological resolution of a racemate (R,S)-α-ethyl-2-oxo-1-pyrrolidineacetic acid ethyl ester to prepare high optically pure (S)-α-ethyl-2-oxo-1-pyrrolidineacetic acid ethyl ester, which is further subjected to a hydrolysis reaction to obtain (S)-α-ethyl-2-oxo-1-pyrrolidineacetate. The present invention achieves a high conversion yield up to 50.0% or more, a good stereoselectivity, and an enantiomeric excess value e.e..sub.s (%) of (S)-α-ethyl-2-oxo-1-pyrrolidineacetic acid ethyl ester not less than 99.5; the catalytic efficiency is high; the concentration of the racemic substrate in the resolution reaction is up to 500 g/L, the reaction time does not exceed 15 h, the number of reuse times of the immobilized cells is not lower than 35.

The invention discloses a strain of Acinetobacter and use thereof in the production of chiral 3-cyclohexene-1-carboxylic acid. Its taxonomic name is Acinetobacter sp., which is deposited on Jan. 21, 2019 at the China General Microbiological Culture Collection Center, under accession number CGMCC No. 17220. Using the Acinetobacter strain of the invention to produce chiral methyl 3-cyclohexene-1-carboxylate, the resulting methyl (S)-3-cyclohexene-1-carboxylate has an optical purity of 99% or more, and the catalyst has good stability, mild reaction condition and can withstand high concentrations of substrate and product. Using the resolution process of the invention, (S)-3-cyclohexene-1-carboxylic acid with high optical purity and high concentration can be simply and efficiently obtained, and the process is energy-saving and environmentally friendly, and the high-concentration of product is beneficial to downstream product recovery process. The invention provides an efficient method for production of (S)-3-cyclohexene-1-carboxylic acid, and has a good industrial application prospect.

The invention provides a new enzimatic process for the preparation of chiral carboxylic acids, their salts and acid derivatives of the general formula (I) by enzymatic hydrolysis of racemic carboxylic acid ester of the general formula (II) and optionally subsequent esterification or acylation.

Disclosed are methods of synthesizing racemic 2-(difluoromethyl)-1-(alkoxycarbonyl)-cyclopropanecarboxylic acids and 2-(vinyl)-1-(alkoxycarbonyl)-cyclopropanecarboxylic acids and their salts, such as the dicyclohexylamine salt. Also disclosed are methods for preparing enantioenriched (1R,2R)-1-((tert-butoxycarbonyl)amino)-2-(difluoromethyl)cyclopropane-1-carboxylic acid and esters of the same. These compounds are useful intermediates in the synthesis of viral protease inhibitors.

The present invention provides a novel hydrolase that can industrially produce optically highly pure (1S,2S)-1-alkoxycarbonyl-2-vinylcyclopropane carboxylic acid with high efficiency at low costs, and a production method using the hydrolase.

The invention provides a new enzimatic process for the preparation of chiral carboxylic acids, their salts and acid derivatives of the general formula (I) by enzymatic hydrolysis of racemic carboxylic acid ester of the general formula (II) and optionally subsequent esterification or acylation.