Synthesis and Preferred Conformations of All Regio- and Diastereoisomeric Methyl 2,3-Fluorohydroxyalkanoates
作者:Wibke S. Husstedt、Susanne Wiehle、Christian Stillig、Klaus Bergander、Stefan Grimme、Günter Haufe
DOI:10.1002/ejoc.201001224
日期:2011.1
Selective syntheses of enantiopure regio- and diastereomeric methyl 2,3-fluoro-hydroxyalkanoates via four different routes employing two types of fluorination reagents are reported. The anti- and syn-3-fluoro-2-hydroxyalkanoates 1 and 3 were prepared by treating the corresponding epoxides with Olah's reagent (Py·9HF). Cyclic sulfates prepared from the enantiomeric diols were ring-opened with TBAF to give the
报道了使用两种类型的氟化试剂通过四种不同的路线选择性合成对映体纯区域和非对映异构体 2,3-氟-羟基链烷酸甲酯。反-和顺-3-氟-2-羟基链烷酸酯1和3是通过用Olah试剂(Py·9HF)处理相应的环氧化物来制备的。由对映体二醇制备的环状硫酸盐用 TBAF 开环得到 anfi- 和 syn-2-fluoro-3-hydroxyalkanoates 2 和 4。立体化学分析主要通过 NMR 光谱进行。应用DFT/B3LYP和SCS-MP2量子化学方法,计算了构象异构体的耦合常数和相对能量。使用 COSMO 连续模型考虑溶剂效应。