A method for preparing trans-D-chrysanthemic acid

Abstract

The invention provides a method for preparing trans-D-chrysanthemic acid, which belongs to the field of organic synthesis. The method of the present invention is that 2-methyl-5,5,5-trichloro-2-pentene and ethyl diazoacetate are synthesized by an asymmetric cyclopropanation reaction to trans-derothrin, and then hydrolyzed to generate trans- D-V-chrysanthemic acid (DV-chrysanthemic acid). The chiral ruthenium catalyst used is generated in situ by ruthenium salts and chiral tridentate P,N,N-ligands in various polar and non-polar solvents. The present invention can conveniently synthesize trans D-chrysanthemic acid (DV-chrysanthemic acid), and its enantiomeric excess percentage is as high as 90%. The invention has the characteristics of simple operation, readily available raw materials, wide application range of substrates, high enantioselectivity and the like.

Description

A kind of method for preparing trans-dextrinic acid technical field The invention belongs to the field of organic synthesis, be specifically related to a kind of method of preparing trans-dextrinic acid. Background technique Trans-D-Chrysanthemum acid (DV chrysanthemic acid) is an important organic synthesis intermediate, can be used for the preparation of various bioactive natural and unnatural compounds. In recent years, organic chemists at home and abroad have synthesized chiral ligands with different frameworks to control A lot of work has been done on the preparation of chiral chrysanthemic acid by asymmetric cyclopropanation, and great success has been achieved. As early as 1966, Nozaki catalyzed styrene and diazoacetic acid through the catalyst formed by Schiff base and transition metal. Asymmetric cyclopropanation of esters yielding ee values ​​of 10% (cis‑) and 6% (trans‑). The reaction tells people: Transition Chiral ligands in metal complexes can induc...

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Problems solved by technology

However, these systems have problems such as low reactivity, harsh reaction conditions, and high cost of ligands. Therefore, it is of great significance to develop a low-cost, high-activity, high-stereoselective asymmetric cyclopropanation method for ligand synthesis.

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