In order to apply Site-specific Natural Isotope Fractionation (SNIF) to chemical, biochemical, and environmental studies of n-glucose, there is a need for readily prepared compounds which give *H NMR spectra with all or most signals resolved. Changing substituents at C-l and/or C-6 of a-o-glucopyranose pentaacetate improved the dispersion of deuterium signals, the best results being achieved with 1,2,3,4-tetra-O-acetl-6-deoxy-6-thiocyaanose, for which only the *H-2 and *H-4 signals were not resolved, and with 2,3,4-tri-0-acetyl-6-bromo-6-deoxy~-o-glucopyranosyl bromide, for which only the *H-6a and *H-6b signals were not resolved. Periodate oxidation of methyl 4,60benzylidene-o-o-glucopyranoside and 4,6-dichloro-4,6-dideoxy-p-galactose was also examined as a possible source of useful compounds. Products obtained from the benzylideneglucoside gave inadequate resolution and broad deuterium signals. The oxidation of 4,6-dichloro-4,6-dideoxy-n-galactose was not straightforward. The a anomer was oxidised more rapidly than the /3 anomer. The oxidation product, 2,4-dichloro-2,4-dideoxy-3-0-formyl-n-threose, was too labile to be isolated pure and its hydrolysis to 2,4-dichloro-2,4-dideoxy-n-threose was accompanied by a slow elimination to form 2,4-dichlorobut-2enal.