Fmoc N-hydroxysuccinimide ester is an efficient reagent for the selective preparation of N-(9-fluorenylmethoxycarbonyl) derivatives of hydroxy-amino acids in high yield. Dipeptide formation is lower than with chloroformate, Fmoc-Cl. It has been used in the synthesis of glycopeptides.An efficient reagent for the selective preparation of N-(9-fluorenylmethoxycarbonyl) derivatives. Fmoc N-hydroxysuccinimide ester is an efficient reagent for the selective preparation of N-(9-fluorenylmethoxycarbonyl) derivatives of hydroxy-amino acids in high yield. Dipeptide formation is lower than with chloroformate, Fmoc-Cl. It has been used in the synthesis of glycopeptides. An efficient reagent for the selective preparation of N-(9-fluorenylmethoxycarbonyl) derivatives.