Methyl a-B-galactopyranoside carbonate solution at 50°.
(1.0 g) was dissolved in 50 ml of O.lM sodium
solution in small portions.
(3-5.0 g) was added to this
The amount of.potassium
of the preparation.
determined by paper chromatography
exchange resin and evaporated The product was separated methanol or ethanol.
in 6:4:3 v/v 1-butanol-pyridine-water
by treatment with Amberlite
ferric hydroxide by extraction with at 209 nm, indicating
with some unreacted
in aqueous solution at room temperature. presumably
was oxidized with sodium hypoiodite6
to 7.5-8.0 with barium hydroxide
or sodium chlorite
in hot water, and the precipitation
(2 0.3, water);
to about 100 ml and a-p-
It was then
and washing were repeated.
(c 1.03, water), stable as high as Finally,
and the solution was treated with Amberlite
exchange resin or sulfuric acid to remove barium ions. gave a colorless syrup which crystallized methyl a-g-galactopyranosiduronic +128O
up to 220-225' but turned light brown about ZOO';
215', turning light brown at about 200'. in hot water,
The pH of the eluate was adjusted
which was washed well with 75% ethanol.
did not melt at temperatures
and then passed through a column of
filtered; 2-3 volumes of ethanol were added to precipitate galactopyranosiduronate
containing mainly methyl a-g-galacto-hexodialdo-
sodium methyl a-_P-galactopyranosiduronate
under diminished pressure at low temperature
It had a strong absorbance
The oxidation product could be reduced to the starting material with
the solution was centrifuged;
presence of sn aldehyde group, but was contaminated compound.
ferrate used depended upon
After reaction was complete as
spraying with silver nitrate and sodium hydroxide, and the filtrate was neutralized
Removal of the solvent
after cooling; yield 0.4 g (40%) of 3o +1400 [a),
(c 2.0, water), mp 107-108".
(2 2.0, water), mp 105-106';
acid using the above procedure; [a], +57O
glucopyranosiduronic calcium salt
separated by prepara-
(2 0.16, water).
+24='), followed by conversion
([a]E5 +39O), evaporation,
[a]B 25 +16-+26'.
to be methyl a-pPreparation
to the free acid with Amberlite
drying and redissolution,
The faster moving component was assumed to be a lactone(s).
Barker -et al. lo prepared
the sodium salt of methyl Neither
Easty'l made the barium salt.
Time‘11 --* et al l6 reported
reported any physical
In most ferrate oxidations,
the main product,
after long reaction times, nor oxidized
was not an acid, and from which no 2,4-dinitrophenyl-
could be formed.
(5 1.0, water).
was a compound that could not be reduced with sodium borohydride with sodium hypoiodite,
the acid to be a syrup that was probably a mixture
the free acid and lactones;
on Silica Gel H with 7:2:1 v/v ethyl acetate-
The slower moving compound, believed
(2 0.14, water), mp 120-123°;
was also oxidized using the same procedure.
The resulting pale yellow syrup contained
(c 1.4, water), mp 114-115O.
had lower Rf values and are, per-
or, more likely, a dimer or higher polymerization
That they arise from ketones has not been ruled out. References 3, 279 (1971).
R. J. Audette,
J. W. Quail, and P. J. Smith, Tetra. Letters,
J. N. BeMiller
and S. D. Darling, U.S. Patent
R. Ii. Wood, J. Amer. Chem. Sot., 80, 2038
J. M. Schreyer and L. T. Ockennan, Anal. Chem., 23, 1312 (1951).
M. L. Wolfrom
T. P. Nevell, Methods
S. Morel1 and K. P. Link, J. Biol. Chem., 100, 385 (1933).
and A. Thompson, Methods
and H. S. Isbell, Methods Carbohyd.
Chem., 2, 67 (1963). Chem., 2, 11 (1963).
Chem., 3, 182 (1963).
C. A. Marsh, J. Chem. Sot., 1578 (1952). T. E. Timell, W. Enterman,
F. Spencer, end E. J. Soltes, Can. J. Chem., 43,
2296 (1965). 11.
S. A. Barker, E. J. Bourne, and M. Stacey, Chem. Ind.
D. B. Easty, J. Org. Chem., 27, 2102