Synthesis of protected norcysteines for SPPS compatible with Fmoc-strategy.
We report the synthesis of racemic Alloc-Ncy(Tmob)-OH, the resolution of its methyl ester, and demonstrate its application to form a norcystine bridge in octreotide-amide using the Fmoc-strategy on solid phase. N-Alloc and S-Tmob protections of norcysteine (Ncy) were found to be a preferred choice for Fmoc-strategy over three other protected norcysteines synthesized i.e. Fmoc-Ncy(tBu)-OH, Alloc-Ncy(tBu)-OH and Alloc-Ncy(Trt)-OH.
Samant
Manoj P
MP
The Clayton Foundation Laboratories for Peptide Biology, The Salk Institute, La Jolla, California 92037, USA.
Rivier
Jean E
JE