Reaction of 8,8-dibromobicyclo[5.1.0]octanes with higher-order organocuprates

Treatment of 8, 8-dibromobicyclo [5.1.0] octanes (A) with a higher order organocuprate prepared from cuprous thiocyanate (method A) or cuprous cyanide (method B) and methyllithium, followed by the addition of methyl iodide in situ, readily afforded 8, 8-dimethylbicyclo [5.1.0] octanes (B) in good yields. The results are summarized in Table I. Interestingly, reaction of the cisdibromides (4 and 19) under the present conditions gave tricyclic compounds (15 and 16, and 20, respectively)