5-烷氧基-3,4-二卤-2(5H)-呋喃酮与脂肪胺类的反应研究

Research on the Reaction of 5-Alkyloxy-3,4-dihalo-2(5H)-furanones with Aliphatic Amines

在氟化钾作催化剂和四氢呋喃作溶剂的条件下,研究了系列脂肪胺亲核试剂与5-烷氧基-3,4-二卤-2(5H)-呋喃酮发生的反应,通过旋光度,UV-Vis,IR,1H NMR,13C NMR,MS,元素分析和X射线单晶衍射等表征方法对产物进行结构表征,发现通常情况下发生预期的串联迈克尔加成-消除反应,合成了13个新的β-胺基-2(5H)-呋喃酮.但是,空间位阻较大的二环己基胺与5-烷氧基-3,4-二卤-2(5H)-呋喃酮反应时,却得到了4个异常的2(5H)-呋喃酮开环产物,其可能是经开环重排反应的机理得到的.

Using KF as catalyst and tetrahydrofuran as solvent,5-alkyloxy-3,4-dihalo-2（5H）-furanones was reacted with sev-eral aliphatic amines.The chemical structures and absolute configurations of the products were confirmed via rotation,UV-Vis,IR,1H NMR,13C NMR,MS techniques,elemental analysis and X-ray single crystal diffraction.Thirteen new normal products β-amino-2（5H）-furanones were obtained via the tandem Michael addition-elimination reaction as anticipated in most cases.However,the reaction between the larger steric dicyclohexyl amine and 5-alkyloxy-3,4-dihalo-2（5H）-furanones yielded four new abnormal products,（E）-alkyl 2-halo-4-dicyclohexylamino-4-oxobut-2-enoate.The possible mechanism for the for-mation of 2（5H）-furanone ring-opening products involving in the rearrangement reaction was proposed.