Asymmetric Michael additions via SAMP-/RAMP-hydrazones enantioselective synthesis of 2-substituted 4-oxosulfones
作者:Dieter Enders、Kyriakos Papadopoulos、Eberhardt Herdtweck
DOI:10.1016/s0040-4020(01)80538-x
日期:1993.2
A simple and efficient enantioselective synthesis of 2-substituted 4-oxosulfones 5 in 40 – 71% overall chemical yield and enantiomeric excesses of 86->97% is described. The key step is an asymmetric Michael-addition of lithiated methylketone -SAMP-/RAMP-hydrazones 3 to α,β-unsaturated phenylsulfones 2. The absolute configuration is determined by X-ray structure analysis of a crystalline hydrazone Michael
描述了一种简单有效的2-取代的4-氧砜5的对映体选择性合成方法,其化学收率为40-71 %,对映体过量为86-> 97%。关键步骤是将锂化的甲基酮-SAMP- / RAMP-hydr 3不对称地与α,β-不饱和苯砜2迈克尔加成。通过结晶迈克尔加合物(4k)的X射线结构分析和通过旋光法的化学相关性来确定绝对构型。