Synthesis of N-Fmoc-O-(N′-Boc-N′-methyl)-aminohomoserine, an amino acid for the facile preparation of neoglycopeptides

The synthesis of N-Fmoc-O-(N'-Boc-N'-methyl)-aminohomoserine in 35% overall yield from L-homoserine is described. This amino acid can be efficiently incorporated into peptides using Fmoc-chemistry-based solid-phase peptide synthesis, and the resulting peptides can be chemoselectively glycosylated at the aminooxy side chains to generate neoglycopeptides. The synthesis of this derivative greatly expands the availability of a previously developed neoglycopeptide synthesis strategy.