1. a Organic Synthesis Department , BioCarb Technology AB , S-223 70, Lund , Sweden
2. b Organic Chemistry II , The Lund Institute of Technology , P.O. Box 124, S-221 00 , Lund , Sweden
3. c CIBA, CRL , CH-4002, Basel , Switzerland
4. d Ferring AB , Box 30561 S-200 62 Malmö, Sweden
5. e Symbicom AB, IDEON , S-223 70, Lund , Sweden
6. f Cytel Corporation , 3525 John Hopkins Court, San Diego , CA , 92121 , USA