THE SYNTHESIS AND SOME PROPERTIES OF 3H-CYCLOHEPT[a]AZULEN-3-ONE

Abstract
3H-Cyclohept[a]azulen-3-one (azuleno[1,2-d]tropone) (1) was synthesized, starting from 2-styrylazulene (2). In trifluoroacetic or dil. sulfuric acid, 1 exists in hydroxycyclohept[a]azulenylium ion (A1), while it exists in a dication (C) in cone. sulfuric acid.