A New Carbanionic One Carbon Ring Enlargement-Alkylation of Lactams

Thelithium-bromine exchange of bicyclic bromo-substituted gamma- and delta-lactams has been investigated finding that the lithium intermediates undergo a ring-enlargement reaction eventually leading to the isomeric six- and seven-membered lactams. Interception of the lithium species with electrophiles allows the synthesis of a series of functionalized quinolinones and benzoazepines