Enantioselective Preparation of
γ
‐Amino Acids and
γ
‐Lactams from Nitro Olefins and Carboxylic Acids, with the Valine‐Derived 4‐Isopropyl‐5,5‐diphenyl‐1,3‐oxazolidin‐2‐one as an Auxiliary
Enantioselective Preparation of
γ
‐Amino Acids and
γ
‐Lactams from Nitro Olefins and Carboxylic Acids, with the Valine‐Derived 4‐Isopropyl‐5,5‐diphenyl‐1,3‐oxazolidin‐2‐one as an Auxiliary
Diastereoselective Conjugate Addition of Cyanide to α,β-Unsaturated Oxazolidinones: Enantioselective Synthesis of <i>ent</i>-Pregabalin and Baclofen
作者:Alan Armstrong、Nicola Convine、Matthew Popkin
DOI:10.1055/s-2006-941584
日期:2006.6
Conjugate addition of cyanide to chiral α,β-unsaturated oxazolidinones catalyzed by samarium(III) isopropoxide proceeds with good diastereoselectivity. The addition products can be converted into the biologically active targets ent-pregabalin and baclofen.
Multisiteorganic–inorganichybridcatalysts have been prepared and applied in a new general, practical, and sustainable synthetic procedure toward industrially relevant GABA derivatives. The domino sequence is composed of seven chemical transformations which are performed in two one‐pot reactions. The method produces both enantiomeric forms of the product in high enantiopurity as well as the racemate
A highly efficient N,N′-dioxide/Gd(III) complex has been developed for the enantioselective conjugate addition of nitroalkanes to α,β-unsaturated pyrazolamides. Under mild reaction conditions, a series of γ-nitropyrazolamides were obtained in good to excellent yields (up to 99%) with excellent enantioselectivities (up to 99% ee). What’s more, the optically active products could be easily transformed
The present invention relates to a method for preparing pregabalin by a biological enzyme method. In particular, the method comprises producing pregabalin B and an R-configuration compound C by using a compound A as a raw material under the action of a biological enzyme; performing configuration inversion of the separated and recovered R-configuration compound C under the action of an isomerase to produce an S-configuration compound D; and producing pregabalin B from the compound D under the action of a biological enzyme
During the process development of Pregabalin 1, a known anticonvulsantdrug, six potential impurities were identified in the final crude material ranging from 0.01 to 0.15% by LCMS. All six impurities were subsequently synthesized and characterized by IR, MS and NMR spectral data. Four of the six related substances are known as 4-isobutylpyrrolidin-2-one 6, 3- isobutylglutaric acid 2, (R)-(-)-3-ca