Synthesis and Dehydrobromination of 3-Bromomethyl- and 3-Bromo-3-methoxymethylcyclobutane-1-carbonitriles and Methyl 3-Bromomethyl- and 3-Bromo-3-methoxymethylcyclobutane-1-carboxylates.

The anti-Markownikoff products of bromination and bromomethoxylation of 3-methylenecyclobutane-1-carbonitrile and methyl 3-methylenecyclobutane-1-carboxylate were subjected to dehydrobromination by the action of potassium tert-butoxide in THF. The reaction takes two elimination pathways: 1,3-dehydrobromination to give bicyclobutane derivatives and 1,2-dehydrobromination leading to substituted methylenecyclobutane. Structural factors in the substrate were revealed, which are responsible for the ratio of the two concurrent elimination processes. [ABSTRACT FROM AUTHOR]