Synthesis of ( Z )-α-chloro-α,β-unsaturated esters with complete stereoselectivity promoted by samarium diiodide
摘要:
Stereoselective beta-elimination in alpha,alpha-dichloro-beta-hydroxyesters 2 was achieved by using samarium diiodide, yielding (Z)-alpha-chloro-alpha, beta-unsaturated esters 1. The starting compounds 2 were easily prepared by reaction of the lithium enolate of ethyl dichloroacetate with different aldehydes at -78 degreesC. A mechanism to explain this process is proposed. (C) 2004 Elsevier Ltd. All rights reserved.
Synthesis of ( Z )-α-chloro-α,β-unsaturated esters with complete stereoselectivity promoted by samarium diiodide
作者:José M. Concellón、Mónica Huerta、Ricardo Llavona
DOI:10.1016/j.tetlet.2004.04.101
日期:2004.6
Stereoselective beta-elimination in alpha,alpha-dichloro-beta-hydroxyesters 2 was achieved by using samarium diiodide, yielding (Z)-alpha-chloro-alpha, beta-unsaturated esters 1. The starting compounds 2 were easily prepared by reaction of the lithium enolate of ethyl dichloroacetate with different aldehydes at -78 degreesC. A mechanism to explain this process is proposed. (C) 2004 Elsevier Ltd. All rights reserved.
Asymmetric Reduction of α,α‐Dichloro‐β‐Keto Esters by NADPH‐Dependent Ketoreductases
作者:Vasileios Giannopoulos、Ioulia Smonou
DOI:10.1002/ejoc.202200410
日期:2022.7.21
In this work a valuable enzymatic method for the stereoselective reduction of α,α-dichloro-β-keto esters was developed. Exclusively the (S)-α,α-dichloro-β-hydroxy esters have been produced using ketoreductases, exhibiting excellent enantioselectivities (>99 % ee) and high yields (conv. >99 %).
在这项工作中,开发了一种有价值的酶促方法,用于立体选择性还原 α,α-二氯-β-酮酯。仅使用酮还原酶生产( S )-α,α-二氯-β-羟基酯,表现出优异的对映选择性 (>99 % ee ) 和高产率 (conv. >99 %)。