A facile, one-pot synthesis of β-(benz[a]azulen-10-yl)-α,β-unsaturatedketones from the corresponding o-(2-furyl)cycloheptatrienylbenzenes is reported. A mechanism involving a novel ring-opening cyclisation reaction by the intramolecular attack of the tropylium ion to the 2-position of the furan ring is proposed.
据报道,由相应的邻-(2-呋喃基)环庚三烯基苯可方便地一锅合成β-(苯并[ a ] azulen-10-基)-α,β-不饱和酮。提出了一种涉及新的开环环化反应的机理,该环化反应是由对苯二甲基离子的分子内攻击呋喃环的2位引起的。
A novel synthesis of β-(10-benz[a]azulenyl)-α,β-unsaturated ketones by intramolecular cyclization of o-[2-furyl]cycloheptatrienylbenzenes
Treatment of o-[2-furyl]cycloheptatrienylbenzenes with triphenylmethyl tetrafluoroborate (trityl salt) in dichloromethane gave β-(10-benz[a]azulenyl)-α,β-unsaturatedketones in one-pot, in which a novelcyclization involving intramolecular attack of tropylium ion to the α-position of furan ring is postulated.
在二氯甲烷中用四氟硼酸三苯甲基酯(三苯甲基盐)处理邻-[2-呋喃基]环庚三烯基苯,得到一锅内β-(10-苯并[ a ] azulenyl)-α,β-不饱和酮,其中涉及分子内的新型环化反应假定对yl离子对呋喃环的α-位的侵袭。