以四氢呋喃为醛基砌块合成(E)⁃α⁃羟乙基⁃α,β⁃不饱和醛

Synthesis of(E)-α-Hydroxyethyl-α,β-unsaturated Aldehydes with Tetrahydrofuran as Carbonyl Source

以四氢呋喃(THF)为醛基砌块,铜为催化剂,过氧化叔丁醇(TBHP)为氧化剂,将THF氧化为2-羟基四氢呋喃,继而开环异构化为4-羟基丁醛,在酸催化下与乙醇胺作用形成亚胺中间体(M);以苄醇为底物,通过铜催化氧化反应得到苯甲醛,进而与M反应得到立体专一的(E)-α-羟乙基-α,β-不饱和醛;利用二维相关谱确认了产物构型.对反应底物进行了拓展,结果表明,该方法能够有效合成官能化的α,β-不饱和醛.本文发展的合成方法具有底物范围广及合成工艺简单等优势.

In this paper,THF was used as carbonyl source and tert-butyl hydroperoxide(TBHP)was used as oxidant to oxidize THF to 2-hydroxytetrahydrofuran,and then isomerization to 4-hydroxybutyraldehyde by ring-opening reaction,then it reacted with ethanolamine under acid catalysis to form imine intermediate(M).On the other hand,benzaldehyde was obtained from benzyl alcohol by copper catalyzed oxidation reaction,and then reacted with M to obtain stereospecific(E)-α-hydroxyethyl-α,β-unsaturated aldehydes,which was further derivatized to obtain theα-functionalizedα,β-unsaturated aldehydes.The configuration of the product was confirmed by COSY(homonuclear chemical shift correlation spectroscopy).Our method has the advantages of low cost and simple synthesis process.