Chelation control in the [3 + 3] annulation reaction of alkoxy-substituted 1,1-diacylcyclopropanes with 1,3-bis(trimethylsilyloxy)-1,3-butadienes. diversity-oriented synthesis of isochromanes.

Functionalized arenes were prepared by chelation-controlled [3 + 3] cyclization/cyclopropane opening reactions of 1-trimethylsilyloxy-1,3-butadienes with benzyloxy- or methoxy-substituted 1,1-diacylcyclopropanes. A number of benzyloxy-substituted derivatives were transformed into isochromanes by deprotection and subsequent cyclization. Mixed chromanes−isochromanes were prepared starting with 1,3-bis(silyloxy)-1,3-butadienes containing a remote chloride group.