8872 J. Am. Chem. Soc., Vol. 122, No. 37, 2000
Oscarson and Sehgelmeble
(2.22 g, 6.57 mmol, 76%). [R]D -65 (c 0.31, CHCl3). 13C NMR
(CDCl3): δ -5.31, -5.35, 14.95, 18.42, 20.75, 25.92, 64.56, 64.68,
77.10, 78.37, 82.90, 94.34. Derivative 7 (2.16 mmol) was tritylated as
6 above to yield (toluene-EtOAc 6:1 + 1% Et3N) ethyl 6-O-tert-
butyldimethylsilyl-1-O-(4,4′-dimethoxytriphenyl)methyl-2-thio-â-D-
fructofuranoside (9) (2.8 g, 3.66 mmol, 96%). [R]D -17 (c 0.39, CHCl3).
NMR (CDCl3, filtered through basic Al2O3): 13C, δ -5.40, -5.47,
14.57, 18.35, 21.45, 25.88, 55.09, 64.32, 67.30, 77.99, 80.68, 82.82,
acceptor 1614 (32 mg, 63 µmol) were coupled according to the general
procedure. Flash chromatography (light petroleum bp 40-65 °C-
EtOAc 10:1) yielded methyl [3-O-benzyl-6-O-tert-butyldiphenylsilyl-
1,4-O-(1,1,3,3-tetraisopropyldisiloxane-1,3-diyl)-â-D-fructofuranosyl]-
(1f 6)-2,3,4-tri-O-benzyl-R-D-mannopyranoside (17, 69 mg, 58 µmol,
92%). NMR (CDCl3): 13C, δ 12.55, 13.48, 13.55, 13.68, 16.96-17.41,
19.24, 26.79, 54.29, 61.76, 62.24, 63.98, 7134, 71.97, 72.30, 72.97,
74.61, 74.73, 79.35, 80.25, 82.38, 87.12, 90.92, 98.42, 109.32, 127.16-
1
1
94.67; H, δ 0.094 (s, 6H), 0.91 (s, 9H), 1.14 (t, 3H), 2.49 (m, 2H),
135.31; H, δ 0.78 (m, 37H), 3.18 (s, 3H), 3.42 (m, 10H), 4.02 (m,
3.31 (d, 1H, J ) 9.9 Hz), 3.37 (d, 1H, J ) 9.9), 3.77 (s, 6H), 3.84 (m,
2H), 3.99 (m, 1H), 4.27-4.28 (m, 2H), 6.83-7.49 (m). Compound 9
(1.98 g, 2.6 mmol) was benzylated as described for compound 8 above
to give, after silica gel column chromatography (toluene-EtOAc 20:1
+ 1% Et3N), ethyl 4-O-benzyl-6-O-tert-butyldimethylsilyl-1-O-(4,4′-
dimethoxytriphenyl)-2-thio-â-D-fructofuranoside (0.42 g, 0.57 mmol,
22%) and ethyl 3-O-benzyl-6-O-tert-butyldimethylsilyl-1-O-(4,4′-
dimethoxytriphenyl)-2-thio-â-D-fructofuranoside (11) (1.06 g, 1.45
mmol, 56%). 11: [R]D 24 (c 0.53, CHCl3). NMR (CDCl3, filtered
through basic Al2O3): 13C, δ -5.39, -5.46, 14.57, 18.35, 21.44, 25.85,
55.07, 64.31, 67.29, 77.97, 80.66, 82.80, 86.63, 94.65, 127.39-137.75;
1H, δ 0.09 (s, 6H), 0.92 (s, 9H), 1.10 (t, 3H), 2.44 (m, 2H), 3.19 (d,
1H, J ) 10.3), 3.58 (d, 1H, J ) 10.3 Hz), 3.75 (s, 6H), 3.80 (m, 2H),
4.02 (m, 1H), 4.41 (d, 1H, J ) 12.1 Hz), 4.46 (m, 2H), 4.55 (d, 1H, J
) 12.1 Hz), 6.77-7.46 (m). Compound 11 (0.64 g, 0.87 mmol) was
detritylated as described for compound 10 above. After silica gel
chromatography (toluene-EtOAc 4:1) ethyl 3-O-benzyl-6-O-tert-
butyldimethylsilyl-2-thio-â-D-fructofuranoside (13, 0.32 g, 0.75 mmol,
87%) was obtained. [R]D -73.3 (c 0.6, CHCl3). NMR (CDCl3, filtered
through basic Al2O3): 13C, δ -4.72, 15.59, 18.97, 21.40, 26.52, 65.26,
3H), 4.42 (m, 7H), 4.79 (d, 1H, J ) 11.2 Hz), 5.57 (s, 1H), 7.01 (m,
30H). Desilylation of 17 according to the general procedure afforded,
after column chromatography (CHCl3-MeOH 10:1) and HPLC (n-
hexanes-EtOAc 1:2), 18 in quantitative yield. [R]D -6.9 (c 1.22,
CHCl3). NMR (CDCl3): 13C, δ 54.83, 61.02, 61.77, 63.43, 71.45, 72.06,
72.40, 72.55, 74.01, 74.50, 74.54, 75.06, 79.89, 81.60, 85.79, 98.82,
103.63, 127.46-136.35; H, δ 3.27 (s, 3H), 3.61 (m, 11H), 4.02 (m,
2H), 4.39 (m, 1H), 4.62 (m, 8H), 7.10 (m, 20H). Anal. Calcd for
C41H48O11: C, 68.70; H, 6.75. Found: C, 68.52; H, 6.92.
1
2,3,3′,4,6-Penta-O-benzylsucrose (22). Donor 14 (100 mg, 0.12
mmol) and acceptor 19 (34 mg, 63 µmol) were coupled according to
the general procedure. The product was purified by flash chromatog-
raphy (toluene-EtOAc 25:1) to produce 2,3,3′,4,6-penta-O-benzyl-6′-
O-tert-butyldiphenylsilyl-1′,4′-O-(1,1,3,3-tetraisopropyldisiloxane-1,3-
diyl)sucrose (20, 54 mg, 43 µmol, 68%). NMR (CDCl3): 13C, δ 12.32,
12.78, 13.34, 13.67, 17.28-17.43, 19.25, 26.80, 60.22, 64.24, 68.08,
70.69, 71.46, 73.15, 73.22, 74.88, 75.28, 78.63, 79.32, 81.73, 81.95,
1
87.77, 91.01, 110.05, 127.28-139.15; H, δ 0.72 (m, 37H), 3.39 (m,
22H), 5.14 (d, 1H, J ) 12 Hz), 5.71 (d, 1H, J ) 3.3 Hz), 6.83 (m,
35H). Donor 15 (43 mg, 63 µmol) and acceptor 19 (34 mg, 63 µmol)
were coupled according to the general procedure and the product was
purified by flash chromatography (toluene-EtOAc, 18:1) to produce
2,3,3′,4,6-penta-O-benzyl-6′-O-tert-butyldimethylsilyl-1′,4′-O-(1,1,3,3-
tetraisopropyldisiloxane-1,3-diyl)sucrose (21, 57 mg, 50 µmol, 80%).
NMR (CDCl3): 13C, δ -5.20, -5.27, 12.31, 13.67, 13.85, 14.56,
17.36-17.64, 18.09, 25.79, 60.03, 60.22, 63.56, 67.98, 70.64, 71.23,
73.09, 73.21, 74.81, 75.17, 77.31, 78.24, 81.63, 81.72, 87.84, 91.01,
1
65.96, 73.53, 78.70, 83.11, 85.93, 94.71, 128.22-138.46; H, δ 0.08
(s, 6H), 0.90 (s, 9H), 1.20 (t, 3H), 2.57 (m, 2H), 3.61 (d, 1H, J ) 12.1
Hz), 3.75-3.89 (m, 5H), 4.27 (d, 1H, J ) 7.1 Hz), 4.46 (t, 1H), 4.67
(d, 1H, J ) 11.8 Hz), 4.80 (d, 1H, J ) 11.8 Hz), 7.26-7.41 (m).
Compound 13 (0.25 g, 0.58 mmol) was acetalized as described for
compound 12 above, to give 15 (0.35 g, 0.52 mmol, 90%) after silica
gel chromatography (light petroleum bp 40-60 °C). [R]D -32.5 (c
0.2, CHCl3). NMR (CDCl3): 13C, δ 12.78, 13.67, 13.85, 14.22, 15.06,
17.64-17.36, 18.30, 22.13, 25.95, 63.94, 64.44, 73.02, 79.14, 86.11,
1
109.92, 127.28-139.15; H, δ -0.15 (s, 6H), 0.7 (m, 37H), 3.38 (m,
12H), 4.32 (m, 10H), 4.96 (d, 1H, J ) 11.8 Hz), 5.27 (d, 1H, J ) 3.5
Hz), 7.14 (m, 25 Hz). Compounds 20 and 21 were desilylated according
to the general procedure. After column chromatography (toluene-
EtOAc, 1:1) and HPLC (CHCl3-MeOH 20:1) 22 was obtained in
quantitative yield. [R]D 2.5 (c 0.66, CHCl3). NMR (CDCl3): 13C, δ
59.17, 63.70, 66.58, 70.69, 71.77, 72.39, 72.56, 73.66, 73.75, 74.47,
76.34, 77.42, 80.84, 80.90, 86.75, 89.71, 103.39, 127.28-138.50; 1H,
δ 3.58 (m, 14H), 4.35 (m, 10H), 4.96 (d, 1H, J ) 11.6 Hz), 5.27 (d,
1H, J ) 3.5 Hz). Anal. Calcd for C47H52O11: C, 71.19; H, 6.61.
Found: C, 71.03; H, 6.45.
1
89.40, 97.89, 127.16-135.31; H, δ 0.08 (s, 6H), 0.90 (m, 9H), 2.69
(q, 2H), 3.72 (m, 2H), 3.86 (d, 1H, J ) 11.7 Hz) 4.17 (d, 1H, J ) 11.7
Hz), 4.28 (s, 1H), 4.63 (m, 3H), 7.21-7.50 (m). Anal. Calcd for
C33H62O6SSi3: C, 59.05; H, 9.31. Found: C, 58.91; H, 9.16.
General Glycosylation Procedure. The acceptor (63 µmol), the
donor (1-2 equiv), and di-tert-butylmethylpyridine (DTBMP, 63 µmol)
were dissolved in distilled CH2Cl2 (5-10 mL) containing crushed
molecular sieves (4 Å, 0.2-0.4 g). The mixture was stirred under argon
for 15 min (at room temperature) after which DMTST (4 equiv) was
added and stirring continued for 2 h. The reaction was quenched by
adding Et3N (0.3 mL), diluted with CH2Cl2 (30 mL), filtered through
Celite, and concentrated. The residue was purified by flash chroma-
tography on a silica gel column.
â-D-Fructofuranosyl r-D-Glucopyranoside, Sucrose (23). Com-
pound 22 (82 mg, 0.1 mmol) was dissolved in MeOH-EtOAc (5:1, 8
mL). Amberlite IR-45(OH-) resin (83 mg) and palladium on activated
carbon were added. The mixture was hydrogenolysed at 110 psi
overnight, filtered twice through Celite, and concentrated. Lyophilisation
of the concentrate gave 23 (34 mg, 0.1 mmol, 100%). NMR data and
optical rotation were identical with data from sucrose.
General Desilylation Procedure. TAS-F17 (1.3 M) in DMF (5 equiv)
was added to a solution of the disaccharide (30-50 µmol) in DMF
(5-8 mL) and the mixture stirred. When TLC indicated the reaction
to be complete (approximately 1 h), the mixture was diluted with EtOAc
(50 mL) and washed with a buffer solution from Reagecon (pH 7, 30
mL). The aqueous layer was extracted with EtOAc (3 × 15 mL), the
combined organic layers were dried and concentrated, and the residue
was purified first by silica gel flash chromatography and then by HPLC.
Methyl (3-O-Benzyl-â-D-fructofuranosyl)-(1f6)-2,3,4-tri-O-ben-
zyl-r-D-mannopyranoside (18). Donor 14 (50 mg, 63 µmol) and
Acknowledgment. This manuscript is dedicated to Professor
R. U. Lemieux on the occasion of his 80th birthday. Financial
support from the Swedish Natural Science Research Council is
gratefully acknowledged.
JA001439U