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, oxidation takes place. Reaction times and product pattern strongly depend on the concentration of O2. Besides biphenyl 2, diphenoquinone 3, and 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 products from 1. The bisphenol 6 was also synthesized by thermolysis of the quinone diazide 11 in the presence of 3.