The (-)-enantiomer is recrystallised from 95% EtOH and dried in a vacuum desiccator. It dissolves in dilute aqueous NaOH and can be precipitated without hydrolysis by acidifying. It forms the N-Na salt in EtOH (by addition of Na to the EtOH solution), and the salt can be methylated with MeI to give the (-)-N-Me lactam with m 80o after recrystallisation from hot H2O and has []D -59.6o (c 5, CHCl3) [Shriner et al. J Am Chem Soc 60 2794 1938]. [Oppolzer et al. Helv Chim Acta 69 1142 1986, Weismiller et al. Org Synth 69 154 1955, Beilstein 27 III/IV 1007.]
