A solution of 2α,3β, in dry DCM (5 mL) was treated with oxalyl chloride (0.07 mL, 0.8 mmol). After stirring for 14 h at room temperature, the solvent was removed under reduced pressure to dryness and the resulting residue was redissolved in dry DCM (5 mL) followed by addition of amino acid (glycine; or glycine methyl ester or; or β-alanine; or 11-aminoundecanoic acid; or methyl 11-aminoundecanoic acid methyl ester;