Asymmetric Syntheses of (−)-3-<i>epi</i>-Fagomine, (2<i>R</i>,3<i>S</i>,4<i>R</i>)-Dihydroxypipecolic Acid, and Several Polyhydroxylated Homopipecolic Acids
作者:Kristína Csatayová、Stephen G. Davies、Ai M. Fletcher、J. Gair Ford、David J. Klauber、Paul M. Roberts、James E. Thomson
DOI:10.1021/jo501952t
日期:2014.11.21
A range of enantiopure polyhydroxylated piperidines, including (2R,3S,4R)-dihydroxypipecolic acid, (−)-3-epi-fagomine, (2S,3S,4R)-dihydroxyhomopipecolic acid, (2S,3R,4R)-dihydroxyhomopipecolic acid, and two trihydroxy-substituted homopipecolic acids, have been prepared using diastereoselective olefinic oxidations of a range of enantiopure tetrahydropyridines as the key step. The requisite substrates
一系列对映纯的多羟基哌啶,包括(2 R,3 S,4 R)-二羟基哌酸,(-)-3-表-fagomine,(2 S,3 S,4 R)-二羟基高烟酸,(2 S,使用一系列对映纯四氢吡啶的非对映选择性烯烃氧化反应制备了3 R,4 R)-二羟基高哌酸和两种三羟基取代的均高哌酸作为关键步骤。必要的基材容易从制备叔-使用我们的非对映选择性加氢胺化或氨基羟基化方案进行山梨酸丁酯,然后进行闭环复分解。所得对映体纯四氢吡啶的非对映选择性烯烃氧化并脱保护后,分离出对映纯多羟基化哌啶为单一非对映异构体(> 99:1 dr),总收率良好。