... Acknowledgments The authors wish to thank Mr. P. Chedd for synthetic assistance, Dr. DJ Merrikin for the biological evalua- tion, and Mrs. SJ Knott and Dr. MJ Pearson for discussions during the preparation of this manuscript. References 1) Bateson, JH; G. Burton & SCM Fell: Synthesis and antibacterial activity of some C-3 lactonyl substituted cephalosporins. Bioorganic and Med. Chem. ...