From pyrrolidin-2-ones to 3-aza-2-oxobicyclo[3.2.0]heptanes. Synthesis of both enantiomers of cis-2-aminomethylcyclobutane carboxylic acid, a conformationally restricted analogue of GABA

Article abstract of DOI:10.1016/S0040-4020(98)01031-X

By changing the cyclisation conditions (NaH in THF or NaOEt in EtOH), an enantiopure malonamide containing an enoate acceptor afforded either diastereomeric pyrrolidin-2-one 3 or 4 as the major product of the intramolecular conjugate addition. After separ