C. Vicent et al.
FULL PAPER
in methanol (Merck), and the resulting mixture was stirred over-
night. TLC (silica; dichloromethane/methanol, 100:20) then
showed the complete consumption of the starting material. The
reaction mixture was concentrated under reduced pressure to yield
a yellow oil; toluene was repeatedly added to the residue, and the
solvents were evaporated. Compound 4 was obtained as a white
solid (52 mg, 0.26 mmol, 40%) that was recrystallised from meth-
anol/diethyl ether. 1H NMR (500 MHz; [D6]acetone/H2O, 15:85;
ferred to the vial containing the sugar by micropipette. The solvent
water was removed by lyophilisation, and a white solid was ob-
tained and recrystallised from methanol/diethyl ether. 1H NMR
(500 MHz; [D6]acetone/H2O, 15:85; 261 K): δ ϭ 8.30 (br. s, 3 H,
NH), 7.41 (m, 2 H, Haryl), 7.24 (m, 3 H, Haryl), 5.70 (s, 1 H, 1-H),
2
4.78 (s, 1 H, 5-H), 4.30 (d, J6endo,6exo ϭ 7.9 Hz, 1 H, 6-Hendo), 3.92
(s, 1 H, 3-H), 3.86 (s, 2 H, 4-H, 6-Hexo), 3.34 (s, 1 H, 2-H) ppm.
2-Ammonio-1,6-anhydro-2-deoxy-β-D-galactopyranose
Bis(3,5-di-
270 K): δ ϭ 8.04 (d, 3JNH,H2 ϭ 8.7 Hz, 1 H, NH), 6.455 (s, 1 H, 4-
tert-butylphenyl) Phosphate (12): Recrystallised 8 (0.19 mmol) was
dissolved in milli-q water in a vial, and a second solution, con-
taining an equimolar quantity of sodium bis(3,5-di-tert-bu-
tylphenyl) phosphate in milli-q water, was prepared. This solution
was then transferred to the vial containing the sugar, by micropip-
ette. The solvent water was removed by lyophilisation, and a white
solid was obtained and recrystallised from methanol/diethyl ether.
1H NMR (500 MHz; [D6]acetone/H2O, 15:85; 270 K): δ ϭ 8.42 (br.
s, 3 H, NH), 7.41 (m, 2 H, Haryl), 7.24 (m, 3 H, Haryl), 6.36 (s, 1
H, OH), 6.27 (s, 1 H, OH), 5.64 (s, 1 H, 1-H), 4.62 (s, 1 H, 5-H),
3
OH), 6.30 (s, 1 H, 3-OH), 5.46 (s, 1 H, 1-H), 4.67 (d, J5,6exo
ϭ
2
5.5 Hz, 1 H, 5-H), 4.22 (d, J6endo,6exo ϭ 7.8 Hz, 1 H, 6-Hendo),
3.79Ϫ3.77 (m, 4 H, 6-Hexo, 2-H, 3-H, 4-H), 2.06 (s, 3 H, CH3) ppm.
2-Acetamido-1,6-anhydro-2-deoxy-β-D-galactopyranose (5): Acetic
anhydride (5 equiv.) was added to
a
stirred solution of
8
(0.47 mmol) in methanol (Merck), and the resulting mixture was
stirred overnight. TLC (silica; dichloromethane/methanol, 100:20)
then showed the complete consumption of the starting material.
The reaction mixture was concentrated under reduced pressure to
yield a yellow oil, toluene was repeatedly added to the residue, and
the solvents were evaporated. Compound 5 was obtained as a white
solid (40 mg, 0.20 mmol, 42%), which was recrystallised from meth-
anol/diethyl ether. 1H NMR (500 MHz; [D6]acetone/H2O, 15:85;
2
4.44 (d, J6endo,6exo ϭ 8.0 Hz, 1 H, 6-Hendo), 4.16 (s, 2 H, 3-H, 4-
H), 3.76 (m, 1 H, 6-Hexo), 3.56 (s, 1 H, 2-H) ppm. ES MS: calcd.
for C18H22NO8P 411.3; found (positive mode): m/z ϭ 412.3 [M
ϩ H]ϩ.
3
270 K): δ ϭ 8.34 (d, 1 H, JNH,2-H ϭ 8.8 Hz, NH), 6.20 (s, 1 H, 3-
Sodium Bis(3,5-di-tert-butylphenyl) Phosphate: Ion-exchange resin
(WA30, Supelco) was placed in a column (gravity packing). A vol-
ume of aqueous hydrochloric acid (2 ) equal to twice the volume
of resin was passed through the column under gravity. Water was
then passed through until the eluent was neutral; this procedure
was repeated, substituting the hydrochloric acid solution with an
aqueous sodium hydroxide solution (2.5 ). The resin was then
washed with methanol, drained of excess solvent and stored until
OH), 5.90 (s, 1 H, 4-OH), 5.42 (s, 1 H, 1-H), 4.54 (d, 3J5,6exo 5.5 Hz,
2
3
1 H, 5-H), 4.42 (d, J6endo,6exo ϭ 7.9 Hz, 1 H, 6-Hendo), 4.09 (d, J2-
ϭ 8.9 Hz, 1 H, 2-H), 4.03 (s, 1 H, 4-H), 3.91 (s, 1 H, 3-H),
H,NH
3.70 (m, 1 H, 6-Hexo), 2.04 (s, 1 H, CH3) ppm. ES MS: calcd. for
C8H13NO 203.1; found (positive mode): m/z ϭ 226.0 [M ϩ Na]ϩ.
2-Ammonio-1,6-anhydro-2-deoxy-β-D-glucopyranose Chloride (9): A
solution of hydrochloric acid in milli-q water (a few drops from a
pipette of concentrated HCl in approximately 5 mL of milli-q
water) was prepared and added dropwise to a solution of recrys-
tallised 7 (0.12 mmol) in milli-q water, until the pH was shown to
be acidic, by spotting (with a fine capillary) onto pH indicator pa-
per. The acidic solution thus obtained was lyophilised to yield a
required.
Bis(3,5-di-tert-butylphenyl)
phosphate
(350 mg,
1.4 mmol) was stirred with a large excess of resin (volume of 2 mL)
in methanol (3 mL) overnight, or until analysis by NMR spectro-
scopy showed that the reaction was complete. [Differences between
the aromatic resonances of bis(3,5-di-tert-butylphenyl) phosphate
and sodium bis(3,5-di-tert-butylphenyl) phosphate allowed the con-
version from the former to the latter to be monitored. 1H NMR
data of bis(3,5-di-tert-butylphenyl) phosphate for comparison with
the corresponding data of sodium bis(3,5-di-tert-butylphenyl)
phosphate: 1H NMR (300 MHz; [D6]DMSO; 299 K): δ ϭ 7.36 (m,
2 H, Haryl), 7.17 (m, 3 H, Haryl) ppm.] The product was isolated
by removing the resin by filtration, concentrating the filtrate and
recrystallising; 90 mg (0.33 mol, 24%) of the salt was collected from
the first recrystallisation. 1H NMR (300 MHz, [D6]DMSO, 299 K):
δ ϭ 7.20 (m, 2 H, Haryl), 7.11 (m, 2 H, Haryl), 6.93 (t, J ϭ 7.0 Hz,
1 H, Haryl) ppm. ES MS: calcd. for C12H10NaO4P 272.2; found
(positive mode): m/z ϭ 295.0 [M ϩ Na]ϩ; found (negative mode):
m/z ϭ 249.1 [M Ϫ Na]ϩ.
1
white solid that was recrystallised from methanol/diethyl ether. H
NMR (500 MHz; [D6]acetone/H2O, 15:85; 261 K): δ ϭ 7.01 (br. s,
1 H, OH), 6.70 (s, 3 H, NH), 6.63 (br. s, 1 H, OH), 5.70 (s, 1 H,
3
2
1-H), 4.76 (d, J5,6exo ϭ 5.5 Hz, 1 H, 5-H), 4.30 (d, J6endo,6exo
ϭ
7.8 Hz, 1 H, 6-Hendo), 3.91 (s, 1 H, 3-H), 3.857 (s, 2 H, 4-H,
6-Hexo), 3.34 (s, 3 H, 2-H) ppm.
2-Ammonio-1,6-anhydro-2-deoxy-β-D-galactopyranose
Chloride
(10): A solution of hydrochloric acid in milli-q water (a few drops
from a pipette of concentrated HCl in approximately 5 mL of milli-
q water) was prepared and added dropwise to a solution of recrys-
tallised 8 (0.19 mmol) in milli-q water, until the pH was shown to
be acidic, by spotting (fine capillary) onto pH indicator paper. The
acidic solution thus obtained was lyophilised to yield a white solid,
which was recrystallised from methanol/diethyl ether. 1H NMR
(500 MHz; [D6]acetone/H2O, 15:85; 270 K): δ ϭ 6.9 (v br. s, 3 H,
NH), 6.35 (br. s, 1 H, OH), 6.25 (br. s, 1 H, OH), 5.63 (s, 1 H, 1-
1
1
3. H NMR Studies in Aqueous Solution: For all H NMR studies
of 4Ϫ12 in aqueous solution, the corresponding monosaccharide
was dried under high vacuum and a temperature of 308 K prior to
1
use. Sample solutions for H NMR spectroscopy were prepared at
2
H), 4.62 (s, 1 H, 5-H), 4.44 (d, J6endo,6exo ϭ 8.0 Hz, 1 H, 6-Hendo),
concentrations ranging from 2 ϫ 10Ϫ3 to 8 ϫ10Ϫ3 , and freshly
filtered milli-q water was always employed. Throughout this work,
the pH of the NMR samples was not varied. All the spectra in
water solution were recorded with solvent suppression; usually, the
WATERGATE pulse sequence was employed, although some spec-
tra were also carried out with presaturation (Cambridge). A prelim-
inary investigation was carried out to select the proper conditions
for the acquisition of spectra of the aqueous sugar solutions. Usu-
ally, as the first step, several NMR spectra were recorded for a
saccharide concentration of around 2 m, employing different
4.16 (s, 2 H, 3-H, 4-H), 3.76 (m, 1 H, 6-Hexo), 3.55 (s, 1 H, 2-H)
ppm. ES MS: calcd. for C6H12NO4Cl 197.6; found (positive mode):
m/z ϭ 162.1 [M Ϫ Cl]ϩ; found (negative mode): m/z ϭ 196.1
[M Ϫ H]ϩ.
2-Ammonio-1,6-anhydro-2-deoxy-β-D-glucopyranose Bis(3,5-di-tert-
butylphenyl) Phosphate (11): Recrystallised 7 (0.12 mmol) was dis-
solved in milli-q water in a vial, and a second solution containing
an equimolar quantity of sodium bis(3,5-di-tert-butylphenyl) phos-
phate in milli-q water was prepared. This solution was then trans-
1934
Eur. J. Org. Chem. 2002, 1925Ϫ1936