1,2,2-Tribromocyclopropanecarboxylic acid and derivatives - Valuable intermediates for four carbon cyclopropane and cyclopropene synthons

Article abstract of DOI:10.1016/0040-4020(95)01123-4

Methyl 1,1,2-tribromocyclopropanecarboxylate is readily available by dibromocyclopropanation of methyl α-bromoacrylate. Reaction with methyllithium at low temperature provides a simple route to methyl 2-bromocyclopropene carboxylate, while modification of the ester group followed by reaction with methyllithium leads to a series of related four-carbon cyclopropenes. The tribromo-ester is also readily converted into 1,1,2,2-tetrabromocyclopropane, a valuable three-carbon cyclopropene synthon.