3-methylcyclohexene (3c) in pentane solution at temperatures from 23°C to −50°C. A preference for addition syn to the directing substituent was observed in reactions of 3a and 3b and was attributed to a reversible interaction of carbene and substituent. In the reaction with 3a this interaction was not obviously ylide formation. © 1997 Elsevier Science Ltd.
在23°C的
戊烷溶液中,在
3-甲氧基环己烯(3a),
3-氯环己烯(3b)和3-甲基
环己烯(3c)的双键中除了1:CH 2之外,还研究了底物取代基的立体定向作用。至-50°C。在3a和3b的反应中观察到优先于顺式取代基的顺式加成,这归因于卡宾和取代基的可逆相互作用。在与3a的反应中,这种相互作用不明显是叶立德形成的。©1997爱思唯尔科学有限公司。