THE SYNTHESIS OF 5H-CYCLOHEPT[a]AZULEN-5-ONE AND ITS NOVEL REACTION WITH A SULFUR YLIDE: THE FORMATION OF A NEW HETEROCYCLIC SYSTEM
5H-Cyclohept[a]azulen-5-one and its 11-methoxycarbonyl derivative were synthesized. The latter reacted in a novel manner with a sulfur ylide to give a new heterocyclic compound having 5-oxa-5H-dicyclohepta[cd,hi] indene skeleton.