An efficient access to (Z)-β-fluoroallyl alcohols based on the two carbon homologation of aromatic aldehydes by Horner–Wadsworth–Emmons reaction with 2-(diethoxyphosphinyl)-2-fluoro-ethanethioic acid, S-ethyl ester followed by reduction with sodium borohydride
作者:Mohammed Kajjout、Rajae Zemmouri、Said Eddarir、Christian Rolando
DOI:10.1016/j.tet.2012.02.039
日期:2012.4
approach to (Z)-β-fluoroallyl alcohols based on the two carbon homologation of aromatic aldehydes to α-fluorocinnamic thioesters by Horner–Wadsworth–Emmons reaction with 2-(diethoxyphosphinyl)-2-fluoro-ethanethioic acid, S-ethyl ester, followed by reduction with sodium borohydride in mild conditions. The α-fluorothioesters were obtained in a good yield by condensing the aldehydes with the lithium anion of
我们描述了一种仿生方法(Z)-β-氟代烯丙醇,其基于霍纳-沃兹沃思-埃蒙斯与2-(二乙氧基膦基)-2-氟代-乙硫基酸S的芳香醛到α-氟代肉桂酸酯的两个碳同系物-乙基酯,然后在温和条件下用硼氢化钠还原。通过将醛与2-(二乙氧基膦基)-2-氟-乙硫酸锂,S-乙酯的锂阴离子在-78°C的THF中缩合,可以以高收率获得α-氟代硫酯。然后将(E,Z)-α-氟肉桂酸硫代酯混合物通过双键异构化通过NaBH 4干净地还原为相应的(Z)-β-氟烯丙基醇在室温下。该方法可以应用于高度官能化的醛,例如可以直接获得(Z)-β-氟松柏油,这是一种从O-糖基化香兰素木质素聚合的强抑制剂。