Efficient Synthesis of Differently Protected Lanthionines via β‐Bromoalanine Derivatives

Lanthionines, thioether‐linked alanines, are readily available from differently protected β‐bromoalanine and cysteine derivatives under phase‐transfer conditions at pH 8.5. Racemisation or elimination of starting materials or products was not observed. Also base‐sensitive protecting groups, such as, for instance, the Fmoc group, were compatible with this procedure, thus conveniently permitting the synthesis of orthogonally protected lanthionines. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)