A Novel Synthesis of Peptide Based on the Photochemistry of 5-Azido-1,3,4-oxadiazoles

Article abstract of DOI:10.1021/ja00342a044

A novel approach to the synthesis of peptides is described.Various N-protected amino acid hydrazides 17 were converted to the salts 18 by condensation with carbon disulfide in methanolic potassium hydroxide.Thermal cyclization of 18 to the heterocycles 19 was followed by reaction with methyl iodide to yield the sulfides 20.After oxidation of 20 to the corresponding sulfones 21, the title compounds 22 were prepared by treating 21 with sodium azide.Deprotection then yielded the free bases 23.Utilization of 22 and 23 in peptide synthesis, relying on a photochemical degradation of the title heterocycle present in these compounds, is described.The scope and limitations of this new methodology are also discussed.