New Stereoconservative Syntheses of β,β,β- and γ,γ,γ-Trifluoro-α-amino, α-Hydroxy, and α-Mercapto Acids and Their Incorporation into a Peptide and Depsipeptide Fragment
作者:Hartmut Schedel、Wojciech Dmowski、Klaus Burger
DOI:10.1055/s-2000-8198
日期:——
Syntheses of β,β,β- and γ,γ,γ-trifluoro-α-amino, α-hydroxy and α-mercapto acids using hexafluoroacetone as protecting and activating reagent are described. The key step of the syntheses is the transformation of an Ï-carboxy group into a trifluoromethyl group on treatment with sulfur tetrafluoride. The carboxy activated species obtained are suitable for direct incorporation into peptide and depsipeptide fragments. RP-HPLC experiments and Mosher's TMPA method (1H and 19F) demonstrate that the reaction sequence occurs without racemization.
描述了使用六氟丙酮作为保护和活化试剂合成β、β、β-和γ、γ、γ-三氟-α-氨基、α-羟基和α-巯基酸。合成的关键步骤是用四氟化硫处理将β-羧基转化为三氟甲基。获得的羧基活化物质适合直接掺入肽和缩酚肽片段中。 RP-HPLC 实验和 Mosher 的 TMPA 方法(1H 和 19F)证明反应序列的发生没有外消旋作用。