... (2) For a review, eg: (a) "Recent Advances in the Chemistry of @-Lactam Antibiotics"; Elks, J., Ed.; The Chemical Society: London, 1977. (b) Muk- erjee, AK; Singh, AK Tetrahedron 1978, 34, 1731-1767. ... See ref 10. (10) Sammes, PG; Smith, S. J. Chem. SOC., Chem. Commun. ...