The reaction of 1-alkenoylcyclopropane carboxylic acids with NBS or NIS was investigated, which provides an efficient route to biologically important 7-halogenated furo[3,2-c]pyran-4-ones in a one-pot transformation. The major pathway for the formation of the O–O heterocycles was proposed as a halo-oxa-cyclization, HBr elimination, cyclopropane ring-opening and recyclization (intramolecular oxa-cyclization), and bromination cascade. The double-oxa-cyclization represents a novel synthetic strategy towards functionalized furo[3,2-c]pyranones.
研究了1-烯炔基
环丙烷羧酸与
NBS或NIS的反应,该反应为在一锅转化中合成具有重要
生物活性的7-卤代
呋喃[3,2-c]
吡喃-4-酮提供了有效途径。研究人员提出了形成O-O杂环的主要途径,即卤代氧杂环化、HBr消除、
环丙烷开环和再循环(分子内氧杂环化)以及
溴化级联反应。双氧杂环化反应是合成功能化
呋喃[3,2-c]
吡喃酮的一种新型合成策略。