Synthesis of 5-oxo-1-substituted tetrazoles derived from amino acids

Abstract

Herein is described an application of amino acid derived isocyanates in the synthesis of 5-oxo-tetrazoles. A series of 1-substituted tetrazol-5-ones have been synthesized by [3+2] cycloaddition of N-Fmoc/Boc/Cbz protected β<i>-</i>amino acid derived isocyanates and TMS-N₃. The protocol has also been extended for the insertion of oxo-tetrazolone moiety in the side chains of the Asp/Glu by employing oxazolidinone bidentate protection for <i style="">C^α</i>and <i style="">N^α</i>groups.