Pavel S. Chelushkin, Ksenia V. Polyanichko, Maria V. Leko, Marina Yu. Dorosh, Thomas Bruckdorfer and Sergey V. Burov

Tetrahedron Letters 2015; 56: 619–622; https://doi.org/10.1016/j.tetlet.2014.12.056

Abstract: Peptide hydrazides can be easily synthesized using a new hydrazone resin, obtained via acylation of aminomethyl polystyrene by Fmoc-hydrazone of pyruvic acid. It was shown that the hydrazone linker is completely stable in the course of standard Fmoc SPPS. Moreover, it can tolerate a treatment with 5% TFA/DCM thus permitting selective removal of Mtt or related acid-labile protecting groups. Subsequent application of cleavage cocktails containing net TFA permits to obtain the desired peptides in a reasonable yields and purity. Synthesized peptide hydrazides can be applied as building blocks for the conjugation with different carrier molecules using hydrazone ligation technique.