Abstract
Upon treatment with a catalytic amount of BF(3)·OEt(2), the reaction between azulene derivatives and epoxides efficiently affords azulenylethanol derivatives. In most cases, this ring-opening transformation proceeds with high regioselectivity, favoring nucleophilic attack at the more substituted position of the epoxide. Stereochemical studies support an S(N)2-type mechanism for the transformation. Furthermore, a preliminary investigation revealed that appropriately substituted oxetanes can also participate in this ring-opening reaction, delivering the corresponding homologated alcohols under similar catalytic conditions.