Asymmetric Synthesis of Fmoc-Protected beta-Hydroxy and beta-Methoxy Amino Acids via a Sharpless Aminohydroxylation Reaction Using FmocNHCI

摘要

An efficient asymmetric synthesis of L-threo-beta-hydroxyasparagine and L-threo-beta-methoxyaspartate that are suitably protected for Fmoc solid phase peptide synthesis is described. The key step in these syntheses was a Sharpless asymmetric aminohydroxylation reaction under basic conditions using N-chlorofluorenyl carbamate (FmocNHCl), a readily prepared and storable nitrogen source.