Tandem InCl3-promoted hydroperoxide rearrangements and nucleophilic additions, a straightforward entry to benzoxacycles

The acid-catalyzed rearrangement of organic peroxides is generally associated to C-C-bond cleavages (Hock and Criegee rearrangements), with the concommittent formation of an oxocarbenium intermediate. This article describes the tandem process between a Hock or Criegee oxidative cleavage and a nucleophilic addition onto the oxocarbenium species (in particular a Sakurai-Hosomi-type allylation), under InCl3 catalysis. It was applied to the synthesis of 2-substituted benzoxacycles (chromanes, benzoxepanes), including a synthesis of the 2-(aminomethyl)chromane part of sarizotan, and a total synthesis of erythrococcamide B.