Practical stereoselective synthesis of α-d-C-mannosyl-(R)-alanine

α-d-C-Mannosyl-(R)-alanine was synthesized in only four steps starting from the known acetonide protected d-ribo-hex-1-enitol and N-benzoylalanine. The key C–C bond formation between the sugar and the amino acid moieties was effected through a Claisen rearrangement of the intermediate oxazole , derived from the ester .