Synthesis and NMR studies of methyl 3-O-[(R)- and (S)-1-carboxyethyl]-α-d-gluco-, galacto- and manno- pyranosides

The title compounds were prepared by condensation of a suitably protected monosaccharide and (R)- or (S)-2-chloropropionic acid followed by removal of the protecting groups. Characterisation by 1H and 13C NMR spectroscopy and NOE difference experiments revealed both chemical shift and enhancement differences between the diastereomers which could be used in determination of the absolute configuration of the 1-carboxyethyl group.