Transformations involving the pyrrolidine ring of nicotine

Abstract
Nicotine was oxidised to cotinine and this successively alkylated and reduced to a series of 4′-mono- and 4′,4′-di-alkylnicotines, the mass spectra of which are discussed. The pyrrolidine ring has been opened with ethyl chloroformate and the product both recyclised to S-nicotine without loss of optical activity and converted to metanicotine. The dihydrochloride of the last, on successive treatment with bromine and sodium hydrogencarbonate, yielded 3′-bromonicotine. Cotinine has been converted into various derivatives, and the demethylation of nicotine has been investigated.