New synthetic route to (S)-(−)-equol through allylic substitution
作者:Yuji Takashima、Yuichi Kobayashi
DOI:10.1016/j.tetlet.2008.06.085
日期:2008.8
Allylic substitution of allylic picolinate 5 with a copper reagent derived from p-MeOC6H4MgBr (6) and CuBr·Me2S produced the anti SN2′ product 7 with high regioselectivity and efficient chirality transfer. Oxidative cleavage of the olefinic function to the alcohol followed by bromination afforded bromide 16, which upon demethylation and intramolecularether ring formation furnished (S)-(−)-equol (3)
用衍生自p -MeOC 6 H 4 MgBr(6)和CuBr·Me 2 S的铜试剂对烯丙基吡啶甲酸5进行烯丙基取代,得到具有高区域选择性和有效手性转移的抗S N 2'产物7。烯烃官能团被氧化裂解为醇,然后溴化,得到溴化物16,该溴化物在脱甲基和形成分子内醚环后提供(S)-(-)-牛尿酚(3)。