Formation of aminosuccinyl derivative from β‐phenacyl aspartyl peptides catalyzed by sodium thiophenoxide

Abstract
In the solid-phase synthesis of cholecystokinin 30-33, Trp-Met-Asp-Phe- amide, the .beta.-phenacyl ester was used to protect the .beta.-carboxyl of aspartyl residue. The ester was cleaved, on the solid support, with a 1 M solution of sodium thiophenoxide in N,N-dimethylformamide, prior to ammonolysis. The product, after purification by countercurrent distribution, was identified as a mixture of isoasparaginyl and aspartyl peptides. A study of the deprotection step, with sodium thiophenoxide, on a model peptide (tert-butyloxycarbonyl-.beta.-phenacyl-aspartyl-phenylalanine-amide) showed the rapid formation of the aminosuccinyl derivative, catalyzed by this reagent.

This publication has 11 references indexed in Scilit: