Abstract
The usual method of formation of tricyclanone (1) involves thermolysis of an intimate mixture of 3-diazocamphor (3) and copper powder and is thought to involve ketocarbene (5).1 Recently this method has been supplemented2 by one which involves reaction of 3,3-dibromocamphor with diethylzinc in benzene where α-elimination to give ketocarbene (5) is mediated by 3-bromocamphor carbanion whose role is indicated by trapping as 3-bromocamphor; this material accounts for ca. 10% of product even after prolonged reaction times.