Synthesis of Fmoc-protected <i style="">β</i>-amino alcohols and peptidyl alcohols from Fmoc-amino acid / peptide acid azides

Abstract

An efficient synthesis of <i style="">N^{<img src='/image/spc_char/alpha.gif' border=0>}</i>-9<i style="">H</i>-fluoren-9-ylmethoxycarbonyl(Fmoc)-<i style="">β</i>-amino alcohols by the reduction of Fmoc-<i style=""><img src='/image/spc_char/alpha.gif' border=0></i>-amino acyl azides employing aqueous NaBH₄ as a reducing agent has been described. The reduction is found to be simple and almost complete. All the Fmoc-<i style="">β</i>-amino alcohols prepared are fully characterized by ¹H and ¹³C NMR and mass spectrometry. Further, the method is extended for the reduction of seven Fmoc-dipeptidyl acids to the corresponding alcohols. Their reduction is also found to be smooth and complete.