1. Department of Chemistry, North Carolina State University, Raleigh, NC 27695–8204, USA
2. H. Zhang, Department of Chemistry, University of North Carolina, Chapel Hill, NC;
3. D. Shan, Chiron Corporation, Thousand Oaks, CA;
4. Department of Pharmaceutical Chemistry, The University of Kansas, Lawrence, KS 66047, USA
Present addresses:
5. O. Gudmundsson, Bristol‐Myers Squibb, New Brunswick, NJ;
6. S. Gangwar, Prolix, Inc., Bothell, WA, USA