已收录 268921 条政策
 政策提纲
  • 暂无提纲
Stereocontrolled synthesis of quaternary β,γ-unsaturated amino acids:: chain extension of D- and L-α-(2-tributylstannyl)vinyl amino acids
[摘要] A pair of diastereomeric (4S,5S)- and (4S,SR)-4-methoxycarbonyl-5-phenylselenomethyl-2-phenyl oxazolines, derived from L-vinylglycine, serve as precursors to protected, quaternary, L- and D-alpha-(2-tributylstannyl)vinyl amino acids, respectively, in three steps {(i) alkylative side chain installation, (ii) eliminative ring-opening and (iii) vinyl selenide to vinyl stannane interconversion}. The title compounds may be protodestannylated to the corresponding free, quaternary L- and D-vinyl amino acids. Alternatively, the 2-stannylvinyl alpha -branch (or the derivative 2-iodovinyl branch) may be exploited to access novel quaternary, L- and D-beta,gamma -unsaturated amino acids via a range of transition metal-mediated cross-coupling reactions. (C) 2001 Elsevier Science Ltd. All rights reserved.
[发布日期] 2001-07-23 [发布机构] 
[效力级别]  [学科分类] 
[关键词] self regeneration of stereocenters;beta,gamma-unsaturated amino acids;vinyl selenides;vinyl stannanes;chain extension [时效性] 
   浏览次数:1      统一登录查看全文      激活码登录查看全文