1-Benzopyrans, such as chromans and chromenes, were prepared in good to excellent yields by using a catalytic amount of p-toluenesulfonic acid through intermolecular cyclization reaction of phenols with unsaturated alcohols in 1,2-dichlroroethane.
Synthesis of Chromans via [3 + 3] Cyclocoupling of Phenols with Allylic Alcohols Using a Mo/<i>o</i>-Chloranil Catalyst System
作者:Yoshihiko Yamamoto、Kouhei Itonaga
DOI:10.1021/ol802800s
日期:2009.2.5
The combination of a molybdenum complex (CpMoCl(CO)(3) or [CpMo(CO)(3)](2)) and o-chloranil was used as a catalyst in the [3 + 3] cyclocoupling of phenols and allylic alcohols under microwave heating conditions. Substituted chromans were selectively obtained in moderate to good isolated yields.