4 results about "Carbonyl reduction" patented technology

This invention relates to the field of asymmetric catalytic hydrogenation, specifically to a method for preparing chiral chromone or chromane carboxylic acid compounds. The method involves preparing a chiral catalyst from a nickel compound and ligands. By controlling the combination of the nickel compound-ligand-solvent, enantioselective hydrogenation of the conjugated C=C bonds of the substrate chromone carboxylic acid compound is achieved, yielding the semi-reduced product chiral chromone carboxylic acid; or, further, the carbonyl group is reduced, and carbonyl reduction and dehydroxylation reactions are carried out at room temperature under trifluoroacetic acid and triethylsilane conditions to obtain the fully reduced product chiral chromane carboxylic acid. The catalytic system of this invention is simple to construct, and the selectivity can be controlled by the solvent system. It maintains high conversion and excellent enantioselectivity even under high S / C conditions, making it suitable for the efficient preparation of chiral chromone / chromane skeletal carboxylic acid compounds.

The present invention provides an estetrol synthesis process, and relates to the technical field of steroid compound synthesis processes, and the method comprises the following steps: taking estrone as an initial raw material, firstly carrying out 3-site hydroxyl protection, and then carrying out an oxidative dehydrogenation reaction in the presence of a metal catalyst and in an oxygen atmosphere to prepare a key intermediate ketene, then 17-site carbonyl reduction, 17-site hydroxyl protection, 15, 16-site double bond dihydroxylation, 3-site protecting group removal and hydrolysis reaction are sequentially carried out, and finally the target product estetrol is obtained. The method adopts metal catalysis to directly oxidize to construct cycloenone, effectively avoids the problem of poor stability of partial intermediates in the prior art, has the advantages of simple process, short reaction steps, greenness, environmental protection and the like, and is suitable for industrial production.

This application discloses a method for synthesizing 2,6-difluorostyrene, belonging to the field of organic chemical synthesis technology, including the following steps: (1) 2,6-dichlorobenzonitrile undergoes a halogen exchange fluorination reaction with a fluorinating agent in a polar aprotic solvent to obtain 2,6-difluorobenzonitrile; (2) the obtained 2,6-difluorobenzonitrile undergoes an addition reaction with methyl magnesium halide in an inert solvent, followed by hydrolysis to obtain 2,6-difluoroacetophenone; (3) the obtained 2,6-difluoroacetophenone undergoes a carbonyl reduction reaction in a solvent to obtain 1-(2,6-difluorophenyl)ethanol; (4) the obtained 1-(2,6-difluorophenyl)ethanol undergoes a dehydration reaction in an alkane solvent under protic acid catalysis to obtain 2,6-difluorostyrene. This synthesis method has the advantages of inexpensive and readily available raw materials, good atom economy, simple reaction operation, high synthesis yield, and good product purity, making it suitable for industrial application.

This invention relates to the field of artificial bear bile powder preparation technology, specifically to a novel 7α-hydroxysteroid dehydrogenase gene R-α-1 and its application in the production and conversion of bear bile powder. This method isolates a novel gene catalyzing asymmetric carbonyl reduction reactions from the feces of Sichuan brown bears. This gene encodes a 7α-hydroxysteroid dehydrogenase, which catalyzes the formation of the intermediate tauroursodeoxycholic acid from tauroursodeoxycholic acid, which is further catalyzed by a 7β-hydroxysteroid dehydrogenase to produce tauroursodeoxycholic acid, the main component of bear bile powder. The nucleotide sequence of this gene is shown in SEQ ID NO.1, and its encoded amino acid sequence is shown in SEQ ID NO.2. This technical solution can solve the technical problem that existing types of 7α-hydroxysteroid dehydrogenases cannot meet the needs of large-scale production due to unsatisfactory enzyme activity and thermostability, and has ideal prospects for widespread application.