Convenient Synthesis of ε-Halo-β-ketoesters and γ,γ‘-Dibromoalkanones by Regio- and Chemoselective Reaction of 2-Alkylidenetetrahydrofurans with Boron Trihalides: A “Ring-Closure/Ring-Cleavage” Strategy
作者:Esen Bellur、Peter Langer
DOI:10.1021/jo047824+
日期:2005.5.1
The reaction of boron tribromide and boron trichloride with 2-alkylidenetetrahydrofurans, readily available on the basis of cyclizations of free and masked dianions with 1,2-dielectrophiles, allowed an efficient synthesis of a variety of carbonyl compounds with remote halide functionality. This includes the chemo- and regioselective synthesis of 6-bromo- and 6-chloro-3-oxoalkanoates and 1,7-dibromoheptan-4-ones
三溴化硼和三氯化硼与2-亚烷基四氢呋喃的反应很容易获得,该反应是基于游离的和掩蔽的二价阴离子与1,2-二亲电子试剂的环化而容易获得的,从而可以有效合成具有远程卤化物官能度的各种羰基化合物。这包括6-溴-3-和6-氯-3-氧代链烷酸酯和1,7-二溴庚烷-4-酮的化学和区域选择性合成。本文概述的方法可被视为“闭环/裂环”策略。