[reaction: see text] 1-Substituted 1-(2,2-diphenylvinyl)cyclopropanes with electron-accepting groups at C1 undergo a novel rearrangement to benzocycloheptenes on triplet-sensitized irradiation. In some instances competition between rearrangement to cyclopentenes and formation of cycloheptenes takes place. When electron-acceptor groups are not present at C1, conventional ring opening to cyclopentenes
[反应:见正文]在三重态敏化辐射下,在C1处具有电子接受基团的1-取代的1-(2,2-二苯基
乙烯基)
环丙烷发生新的重排,生成苯并
环庚烯。在某些情况下,发生重排成
环戊烯和形成
环庚烯之间的竞争。当C 1上不存在电子受体基团时,仅会发生常规的对
环戊烯的开环。对于这种新颖的光反应,提出了一种涉及从二苯基
乙烯基单元到电子受体基团的分子内
SET的机理。