effectively in cyclizations with N-acyliminum species. Electron-attracting substituents other than N-acyl, such as N-sulfonyl, can also be employed in analogues of N-acyliminium ion reactions. However, this review will concentrate on cyclizations of the N-acyl type, encompassing groups such as alkanoyl, aroyl, carbalkoxy, and N,N-dialkylcarbamyl, with limited coverage of sulfonyl groups. Most significantly, this review will focus on intramolecular reactions of N-acyliminium ions that result in the formation of new carbon-carbon bonds, rather than new carbonheteroatom bonds. Although β-lactam synthesis based on the cyclocondensation of imines with acid halides, Bruce E. Maryanoff earned B.S. (1969) and Ph.D. (1972) degrees from Drexel University and then conducted postdoctoral studies at Princeton University, working with Prof. Kurt Mislow. He joined McNeil Laboratories, a Johnson & Johnson subsidiary, in 1974 and advanced to Distinguished Research Fellow, the highest scientific position in the company. From 1976 to 1992, he principally worked on discovering drugs for treating central nervous system disorders; in 1992, he moved into cardiovascular research and presently leads the Vascular Research Team. Dr. Maryanoff is recognized for his work in organic and medicinal chemistry, especially the Wittig olefination reaction; peptides and peptidomimetics; antiepileptics and antidepressants; thrombin inhibitors; and protease-activated receptors. He discovered TOPAMAX topiramate, which is marketed worldwide for the treatment of epilepsy and is being developed for migraine headache. He has published 200 scientific papers, is an inventor on 60 U.S. patents, and has received two national awards, the ACS Heroes of Chemistry Award (2000) and the ACS Award in Industrial Chemistry (2003). Dr. Maryanoff is a Fellow in the American Association for the Advancement of Science and the Royal Society of Chemistry. Han-Cheng Zhang received B.S. and M.S. degrees in chemistry from Xiamen University, P.R.C., and served as a faculty member there for 5 years. He came to the United States and earned a Ph.D. degree in organic chemistry from Rensselaer Polytechnic Institute (1992), working with Prof. Doyle Daves. He joined the R. W. Johnson Pharmaceutical Research Institute as a Postdoctoral Scientist with Dr. Bruce Maryanoff and, after one year, as a Scientist. Dr. Zhang has worked as a medicinal chemist in the areas of G-protein-coupled receptors, proteases, and kinases to discover new drug candidates, recently leading a project that identified the first potent, selective antagonists for the thrombin receptor, proteaseactivated receptor 1. He is now at the level of Principal Scientist in Johnson & Johnson Pharmaceutical Research & Development. Dr. Zhang has published over 40 scientific papers and is an inventor on 13 U.S. patents (issued or pending). His scientific interests include the design and synthesis of novel therapeutic agents, heterocycles, stereoselective reactions, organometallic chemistry, and solid-phase organic synthesis. Judi...

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The bacterial enzyme MurA catalyzes the transfer of enolpyruvate from phosphoenolpyruvate (PEP) to uridine diphospho-N-acetylglucosamine (UNAG), which is the first committed step of bacterial cell wall biosynthesis. From high-throughput screening of a chemical library, three novel inhibitors of the Escherichia coli MurA enzyme were identified: the cyclic disulfide RWJ-3981, the purine analog RWJ-140998, and the pyrazolopyrimidine RWJ-110192. When MurA was preincubated with inhibitor, followed by addition of UNAG and PEP, the 50% inhibitory concentrations (IC 50 s) were 0.2 to 0.9 M, compared to 8.8 M for the known MurA inhibitor, fosfomycin. The three compounds exhibited MICs of 4 to 32 g/ml against Staphylococcus aureus; however, the inhibition of DNA, RNA, and protein synthesis in addition to peptidoglycan synthesis by all three inhibitors indicated that antibacterial activity was not due specifically to MurA inhibition. The presence of UNAG during the MurA and inhibitor preincubation lowered the IC 50 at least fivefold, suggesting that, like fosfomycin, the three compounds may interact with the enzyme in a specific fashion that is enhanced by UNAG. Ultrafiltration and mass spectrometry experiments suggested that the compounds were tightly, but not covalently, associated with MurA. Molecular modeling studies demonstrated that the compounds could fit into the site occupied by fosfomycin; exposure of MurA to each compound reduced the labeling of MurA by tritiated fosfomycin. Taken together, the evidence indicates that these inhibitors may bind noncovalently to the MurA enzyme, at or near the site where fosfomycin binds.

A new class of oxaziridine derivatives, 2-arenesulfonyl-3-aryloxaziridines (2), is prepared by m-CPBA oxidation of sulfonimines (RSOlN=CHAr). These compounds are the first stable examples of this ring system to have a substituent other than carbon attached to nitrogen and are characterized by a highly electrophilic oxaziridine oxygen atom. These oxaziridines have the E configuration as determined by X-ray crystallography. The presence of the powerful electron-attracting sulfonyl group attached to nitrogen apparently has little effect on the structure of the oxaziridine three-membered ring. Of more significance are the observations that the nitrogen lone pair in 2 is opposite to one of the sulfonyl oxygens and that the long S-N bond length implies little if any conjugative interaction between sulfur and nitrogen. Attempts to prepare oxaziridines via oxidation of sulfonimines, 5, derived from acetophenone gave imidoyl ether 14, a novel Baeyer-Villiger oxidation product of a C-N double bond.Three-membered heterocyclic compounds are important synthetic reagents and have played key roles in elucidating the fundamental properties of organic molecules. Unique members of this class of heterocycles are the oxaziridines, compounds containing 0, N , and C atoms in a three-membered ring.Oxaziridines, in general, are highly reactive molecules that display novel and unusual chemistry.2 At present an understanding of the reactions and properties of these compounds, particularly from a mechanistic standpoint, remains undefined.3 Furthermore, the synthetic potential of oxaziridines has yet to be realized. 2-Arenesulfonly-3-aryloxaziridines (2) are a new class of oxaziridines prepared by oxidation of the corresponding sulfonimine, 1, according to eq 1 .4 These compounds are the first A r c 111 m -C P B A NaHCO1-HzO CWCl3

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