Enamines, 1, prepared from cyclohexanones or cyclopentanones are reacted with acrylamide to give lactams, the condensed 2-piperidones, 2. Ethyl 2-(1-pyrrolidinyl)-2-cyclohexene-1-propanoate, 3, when treated with primary amines, produces the corresponding N-substituted 2-piperidones, 4. Ethyl 2-(1-pyrrolidinyl)-2-cyclohexene-1-ethanoates and ethyl 2-(1-pyrrolidinyl)-2-cyclopentene-1-ethanoate, 5, react
Enamines (1) derived from cyclohexanone or cyclopentanone are reacted with electrophilic olefins (ethyl acrylate, ethyl 2-methylacrylate, ethyl 2-butenoate) to give the new enamines, 2. When 2 is reacted with LiAlH4, reductive cyclisation takes place giving hexahydrochromane-8a-amines of octahydrocyclopentapyrane-7a-amines, 3, in quantitative yields. 3 is hydrolyzed with dilute aqueous hydrochloric