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DOI: 10.1055/s-0028-1088013
Enantioselective Synthesis of N-Protected α-Amino Acid Hydrazides
Publikationsverlauf
Received
30 October 2008
Publikationsdatum:
16. März 2009 (online)


Abstract
A new, mild, general, and efficient synthesis of N-protected α-amino acid hydrazides is described. This two-step preparation uses N-aminophthalimide as protected hydrazine to prepare N-protected α-amino acid hydrazide precursors, and subsequent dephthaloylation with an aminomethyl polystyrene resin yields N-protected α-amino acid hydrazides. It has the advantages of avoiding the use of the toxic hydrazine reagent and being compatible with the most commonly used N-protecting groups. This strategy is particularly interesting in the case of N-(9-fluorenylmethoxycarbonyl)-protected amino acids. Within the limits of chiral HPLC detection, no epimerization is apparent.
Key words
amino acids - hydrazides - epimerization - protecting groups - aminomethyl resins