The conformation and rearrangement reactions of derivatives of 10,11-dihydrodibenzoxepin

Abstract

The conformational behaviour of 10-substituted 10,11-dihydrodibenz[b,f]oxepins (V—XVI) has been investigated by n.m.r. spectroscopy. The favoured conformation is shown to be that in which the 10-substituent has the quasi-equatorial conformation with respect to the seven-membered ring. The stereo-electronic requirements for the observed rearrangement reactions of 10-chloro-10,11-dihydrodibenz[b,f]oxepins to give 9-chloromethyldibenzoxanthens are considered in relation to this favoured conformation.