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3-O-Mesyl-1,6-di-O-trityl-i-
D
-fructofuranosyl-(2
Hz, H-6a), 2.75 (s, 3H, OSO2CH3), 3.08 (dd, 1H, J5,6b
1.0 J6a,6b 10.0 Hz, H-6b), 3.22–3.32 (m, 4H, H-1%a,b
and H-6%a,b), 3.88–3.92 (m, 1H, H-5), 4.11–4.16 (m,
1H, H-5%), 4.71 (dd, 1H, J1,2 3.8 J2,3 9.7 Hz, H-2),
5.08–5.22 (m, 3H, H-3,4,4%), 5.25 (d, 1H, J1,2 3.8 Hz,
H-1), 5.92 (d, 1H, J3%4% 4.9 Hz, H-3%) and 7.10–7.40 (m,
45H, Ar-H). 13C NMR: l 170.2, 169.7, 169.1, 168.8
(COCH3), 143.6, 143.3, 143.1, 128.7, 127.9, 127.7,
127.1, 126.8, (Ar-C), 105.1 (C-2%), 90.2 (C-1), 87.3, 87.2,
86.1 (CPh3), 81.0 (C-5%), 79.6 (C-4%), 75.7 (C-3%), 70.6,
69.9, 69.4, 68.3 (C-2,3,4,5), 63.0, 62.4, 60.8 (C-1%,6,6%),
38.2 (OSO2CH3) and 20.7, 20.5, 20.3, 20.3 (COCH3).
HRESIMS (positive mode): calcd for [C78H74O17S+
Na]+ 1337.4544. Found: 1337.4532. Anal. Calcd for
C78H74O17S: C, 71.21; H, 5.67; S, 2.43. Found: C, 71.05;
H, 5.70; S, 2.59.
1)-6-O-trityl-h- -glucopyranoside (3).—To a solution
D
of 6,1%,6%-tri-O-tritylsucrose (1.49 g, 1.39 mmol) in ben-
zene (20 mL) was added dibutyltin oxide (0.35 g, 1.41
mmol). The reaction mixture was heated under
azeotropic distillation overnight and then concentrated
under reduced pressure. The residue was taken up in
dichloromethane (20 mL) and Et3N (0.21 mL, 2.08
mmol), and cooled (0 °C), and then MsCl (0.25 mL,
2.18 mmol) was added dropwise under argon. When
TLC (1:1 EtOAc–hexane) showed that the reaction was
complete (ꢀ0.5 h), workup in the usual way, followed
by flash column chromatography (1:1 EtOAc–hexane),
gave 3 (0.54 g, 34%) as a colorless syrup: [h]2D6 +18.0°
1
(c 0.50, CHCl3); H NMR: l 2.68 (s, 3H, OSO2CH3),
2.98–3.51 (m, 9H, H-2,3,4,1%a,b,6%a,b and 6a,b), 3.70–
3.75 (m, 1H, H-5), 3.95–4.00 (m, 1H, H-5%), 4.45–4.52
(m, 1H, H-4%), 5.07 (d, 1H, J3%,4% 8.4 Hz, H-3%), 5.53 (d,
1H, J1,2 4.2 Hz, H-1) and 7.14–7.40 (m, 45H, Ar-H).
13C NMR: l 143.6, 143.5, 143.2, 128.7, 128.6, 127.9,
127.2, 127.1 (Ar-C), 102.7 (C-2%), 91.0 (C-1), 87.3, 87.2,
87.1 (CPh3), 83.1 (C-5%), 79.6 (C-3%), 74.4 (C-4%), 71.9,
71.4, 71.1, 70.9 (C-2,3,4,5), 64.9, 63.5, 63.1 (C-1%,6,6%)
and 37.8 (OSO2CH3). HRESIMS (positive mode): calcd
for [C70H66O13S+Na]+ 1169.4122. Found 1169.4162.
Anal. Calcd for C70H66O13S: C, 73.27; H, 5.80; S, 2.79.
Found: C, 73.10; H, 5.69; S, 2.52.
3-O-Acetyl-4-bromo-4-deoxy-1,6-di-O-trityl-i-
tagatofuranosyl-(21)-2,3,4-tri-O-acetyl-6-O-trityl-h-
-glucopyranoside (7).—6,1%,6%-Tri-O-tritylsucrose (7.35
D-
D
g, 6.88 mmol) was treated with dibutyltin oxide (1.71 g,
6.87 mmol) as described for 3. The crude stannylene
acetal was stirred in CH2Cl2 (100 mL) and pyridine (7
mL) at −60 °C and trifluoromethanesulfonic anhy-
dride (2.2 mL, 13.4 mmol) was added dropwise under
argon. The temperature was then allowed to rise to
0 °C, and stirring was continued for 10 min. Work up
in the usual manner, followed by flash column chro-
matography (1:1 EtOAc–hexane), gave the correspond-
4-O-Mesyl-1,6-di-O-trityl-i-
D
-fructofuranosyl-(2
1)-6-O-trityl-h- -glucopyranoside (4).—A solution of
D
ing
sucrose.
A mixture of the 4%-O-triflate and lithium bromide
4%-O-trifluoromethanesulfonyl-6,1%,6%-tri-O-trityl-
6,1%,6%-tri-O-tritylsucrose (4.16 g, 3.89 mmol) in toluene
(40 mL) was treated with dibutyltin oxide (0.99 g, 3.98
mmol) and then MsCl (0.50 mL, 4.37 mmol) in the
presence of Et3N (0.50 mL, 4.95 mmol), as described
above to give, after flash column chromatography (1:1
EtOAc–hexane), 4 (2.51g, 56%) which crystallized from
MeOH: mp 104–107 °C (dec.); [h]2D6 +25.3° (c 1.02,
(0.44 g) in acetone (50 mL) was stirred at rt for ꢀ15 h
when TLC (1:1 EtOAc–hexane) revealed that all start-
ing material had reacted. The mixture was concen-
trated, taken up in dichloromethane and filtered. The
organic layer was washed with brine, dried (Na2SO4),
filtered, concentrated, and acetylated using Ac2O in
pyridine. Workup in the usual manner, followed by
column chromatography (1:2 EtOAc–hexane), gave 7
as a yellowish syrup (2.2 g, 25%): [h]2D6 +72.3° (c 1.20,
CHCl3); 1H NMR: l 1.54, 1.71, 1.89, 1.89 (s, 12H,
COCH3), 2.69 (dd, 1H, J5,6a 2.0 J6a,6b 10.0 Hz, H-6a),
3.18 (dd, 1H, J5,6b 2.0 J6a,6b 10.0 Hz, H-6b), 3.25 (s, 2H,
H-1%a,b), 3.32 (dd, 1H, J5%6%a 4.9 J6%a,6%b 10.1 Hz, H-6%a),
3.40 (dd, 1H, J5%6%b 6.6 J6%a,6%b 10.1 Hz, H-6%b), 4.01–4.04
(m, 1H, H-5), 4.19–4.25 (m, 1H, H-5%), 4.52 (t, 1H,
J3%,4%=J4%,5% 5.0 Hz, H-4%), 4.80 (dd, 1H, J1,2 3.5 J2,3 9.7
Hz, H-2), 5.19–5.30 (m, 3H, H-3,3%,4), 5.44 (d, 1H, J1,2
3.5 Hz, H-1) and 7.08–7.33 (m, 45H, Ar-H). 13C NMR:
l 170.3, 169.9, 169.8, 169.0 (COCH3), 143.7, 143.2,
128.7, 128.0, 127.8, 127.3, 126.8 (Ar-C), 104.7 (C-2%),
90.4 (C-1), 87.4, 87.1, 86.1 (CPh3), 78.7 (C-5%), 73.0
(C-3%), 70.8 (C-3), 70.6 (C-2), 69.4 (C-5), 68.6 (C-4),
65.4 (C-6%), 64.7 (C-1%), 60.7 (C-6), 50.0 (C-4%) and 20.8,
20.6, 20.5, 20.4 (COCH3). HRESIMS (positive mode):
calcd for [C77H71O14Br+Na]+ 1321.3925: 1323.3905.
1
acetone); H NMR: l 2.69 (s, 3H, OSO2CH3), 2.72–
2.80 (m, 1H, H-2), 3.15–3.54 (m, 7H, H-3,4,5,1%a,b and
6%a,b), 3.86–4.01 (m, 3H, H-3%, 6%a,b), 4.50 (dd, 1H, J4%5%
8.5 J5%6% 11.6 Hz, H-5%), 5.45 (t, 1H, J3%,4%=J4%,5% 8.5 Hz,
H-4%), 6.00 (d, 1H, J1,2 4.2 Hz, H-1) and 7.22–7.50 (m,
45H, Ar-H). 13C NMR: l 143.4, 143.4, 128.9, 128.7,
127.3, 127.1 (Ar-C), 105.2, (C-2%), 91.4 (C-1), 87.5, 87.3,
87.3 (CPh3), 82.6, (C-5%), 76.5, 76.2 (C-3%,4%), 73.7, 72.3,
70.5, 70.3 (C-2,3,4,5), 65.7, 65.4, 64.0 (C-1%,6,6%) and
38.6 (OSO2CH3). HRESIMS (positive mode): calcd for
[C70H66O13S+Na]+ 1169.4122. Found: 1169.4114.
Anal. Calcd for C70H66O13S: C, 73.27; H, 5.80; S, 2.79.
Found: C, 73.12; H, 5.76; S, 2.55.
3-O-Acetyl-4-O-mesyl-1,6-di-O-trityl-i-
D-fructofuran-
osyl-(21)-2,3,4-tri-O-acetyl-6-O-trityl-h-
D-gluco-
pyranoside (5).—Conventional treatment of 4 (2.3 g,
2.00 mmol) with pyridine and Ac2O gave crystalline 5
(2.3 g, 86%): mp 178–180 °C (dec.) (from Et2O); [h]D26
1
+47.7° (c 0.95, CHCl3); H NMR: l 1.52, 1.83, 1.89,
1.90 (s, 12H, COCH3), 2.68 (dd, 1H, J5,6a 3.1 J6a,6b 10.0