Collect. Czech. Chem. Commun. 1988, 53, 308-310

Rearrangement of five-membered heterocyclic enamines

Otakar Červinka, Anna Fábryová and Tomáš Jursík

Department of Organic Chemistry Prague Institute of Chemical Technology, 166 28 Prague 6


Addition of bromine to 1-methyl-2-benzilidenepyrrolidine (Ia) and subsequent treatment with sodium hydroxide afforded unstable 1-methyl-2-phenyl-3-piperidone (IVa) which was reduced with lithium aluminium hydride to an isolable mixture of diastereoisomeric 1-methyl-2-phenyl-3-piperidinols (Va). Analogous reaction with 1-methyl-2-ethylidenepyrrolidine (Ib) led to mixture of products containing, in addition to diastereoisomeric 1,2-dimethyl-3-piperidinols (Vb), also the substitution products 1-methyl-2-(1-hydroxyethyl)pyrrolidines VI and 1-methyl-2-ethyl-3-pyrrolidinols VII (as detected by mass spectrometry).