BASE-CATALYZED DEHALOGENATION OF 2,6-DI-TERT-BUTYL-4-IODOPHENOL FORMATION AND STRUCTURE OF A NEW OXOCYCLOHEXADIENYLIDENE BISPHENOL

2,6-Di-tert-butyl-4-iodophenol (1) does not react to the keto carbene 4 under strongly basic conditions and exclusion of oxygen, in contrast to a report in the literature. In the presence of oxygen, however, ox idation takes place. Reaction times and product pattern strongly depen d on the concentration of O-2. Besides biphenyI 2, diphenoquinone 3, a nd quinone 5, a new (oxocyclohexadienylidene)bisphenol 6 was isolated, and its molecular structure was determined by X-ray crystallography. A radical mechanism is suggested for the formation of the above produc ts from 1. The bisphenol 6 was also synthesized by thermolysis of the quinone diazide 11 in the presence of 3.