One-step synthesis of novel heptacyclic molecules starting from 2-aryl-4-methyl-1-benzopyrylium salts. X-ray crystal structures of these compounds containing a methano-bridged 1-benzoxepine fused to two 1-benzopyran moieties

The chemical reduction of 4-methyl-2-(ortho-hydroxyaryl)-1-benzopyrylium ch lorides with Zn in MeCN and HCl led to a mixture or diastereoisomeric hepta cyclic molecules. Thr structures of two of them were determined by X-ray an alysis. These methane-bridged 1-benzoxepines fused to two 1-benzopyran moie ties were formed from intermediate biflavene species.