Stereoselective Synthesis of α-Methyl and β-Methyl Pyrrolidine 5,5-trans-Lactam (5-Oxo-hexahydro-pyrrolo[3,2-b]pyrrole) and Stereoselective Alkylation of the Strained Pyrrolidine 5,5-Trans-Lactam Ring System - Borthwick, Alan D; Crame, Andrew J; Davies, David E; Exall, Anne M; Jackson, Deborah L; Mason, Andrew M; Pennell, Andrew M K; Weingarten, Gordon G (Synlett, 2000)