PHOTOCHEMICAL DESULFURIZATION OF L-CYSTEINE DERIVATIVES

Thiol groups can be reductively eliminated at room temperature by a ph otochemical method which make:; use of triethylboron, triethylphosphit e and visible light. Thus, after treating L-Cys 1a, D-Pen 1b, L-Cys-OM e 1c and glutathione (gamma-L-Glu-L-Cys-Gly) 3, the corresponding desu lfurized compounds L-Ala 2a, D-Val 2b, L-Ala-OMe 2e and gamma-L-Glu-L- Ala-Gly 4, respectively, are prepared in high yields and with retentio n of configuration. (C) 1998 Elsevier Science Ltd. All rights reserved .