Mechanism, cyclopropane ring halides

Bridgehead olefins (834 n = 3 or 4) are formed in the solvolysis of the dibromo-propellanes (833 n = 3 or 4) by loss of halide anion, electrocyclic cleavage of the cyclopropane ring, and solvent capture/ The products isolated depend upon the precise reaction conditions in the case of (833 n = 3) acetolysis affords (835 53%) and (836 18 %) provided that water is not present. The details of the mechanism of the Ag" "-assisted solvolysis of (833 n = 4) have been elucidated with the aid of labelling. " ... 

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