244
S. P e´ tursson / Carbohydrate Research 331 (2001) 239–245
ment was 30 °C, which is the temperature used
for both series. The solutions used for the
experiments were stored inside the cell com-
partment between runs. At 1-min intervals the
A523 was recorded. The pseudo first-order rate
constant was determined by plotting ln(A )
Methyl
4,6-O-benzylidene-2-O-diphenyl-
methyl-a-
D
-glucopyranoside (0.312 g 19.6%)
was crystallized from ether–hexane, mp 160–
2
D
2
1
161 °C, [h] +22.4° (c 3.1, CHCl ). H NMR
3
(CDCl
s, ꢀOCH
H-3), 3.58 (1 H, dd, J
): l 2.26 (1 H broad, ꢀOH), 3.33 (3 H,
3
), 3.48 (1 H, t, JH3, H2 and H3, H4 9.3 Hz,
523
3
3.6, JH2, H3 9.3 Hz,
against time using the Microsoft EXCEL
software.
H2, H1
H-2), 3.68 (1 H, t, JH4, H3 and H4, H5 10.2 Hz,
H-4), 3.78–3.84 (1 H, dd, JH6a, H6b 14.2, JH6a,
Ethylene glycol diphenylmethyl ether.—Eth-
ylene glycol (0.25 g, 4.0 mmol) and anhydrous
tin(II) chloride (0.023 g, 0.12 mmol) were
dissolved in 1,2-dimethoxyethane (10 mL). Di-
azodiphenylmethane (0.971 g, 5.00 mmol) was
then added, and the reaction was allowed to
proceed at rt for about 5 h. TLC (4:1 hexane–
H5 4.5 Hz, H-6a), 4.19–4.28 (2 H, m, H-5 and
H-6b), 4.49 (1 H, d, JH1, H2 3.6 Hz, H-1), 5.51
(
(
(
1 H, s, Ph CH), 5.66 (1 H, s, PhCH), 7.3–7.5
2
13
15 H, m, Ar H). C NMR (CDCl ): l 55.31
3
ꢀOCH ), 61.97 (C-3), 68.98 (C-2), 70.32 (C-
3
5
), 79.37 (C-4), 81.25 (C-6), 84.42 (C-1), 98.77
(
Ph CH), 101.89 (PhCH), 126.29, 127.02,
EtOAc) showed the ether product, R 0.13,
2
f
1
27.49, 127.68, 127.89, 128.28, 128.46, 129.16
Ar C-2 to C-6), 137.07 (PhCH Ar C-1),
41.54, 142.07 (Ph C Ar C-1 conformers).
and a faster yellow component, R 0.50. The
f
(
main product was purified on a column of
silica gel to give 0.74 g, 65% yield, of the
monoether product, which solidified on stand-
1
2
Anal. Calcd for C H O : C, 72.3; H, 6.3.
2
7
28
6
Found: C, 72.09; H, 6.24.
ing and was recrystallized from hexane: mp
1
Methyl
4,6-O-benzylidene-3-O-diphenyl-
6
0–61 °C. H NMR (CDCl ): l 2.17 (1 H, s,
3
methyl-a-
D
-glucopyranoside (1.10 g, 69.1%)
OH), 3.46–3.51 (2 H, m, CH ꢀOH), 3.67 (2 H,
2
22
D
1
glass [h] +78.2° (c 11, CHCl ). H NMR
3
t, J 4.6 Hz, Ph CHOCH ), 5.31 (1 H, s,
1
,2
2
2
(
CDCl ): l 3.39 (3 H, s, ꢀOCH ), 3.7–3.9 (6
13
3
3
Ph CH), 7.15–7.29 (10 H, m, Ar H).
C
2
H, m, OH and H-2 to H-6a), 4.25–4.28 (1 H,
NMR (CDCl ): l 61.94, 70.30 (2 C, negative
3
m, H-6b), 4.77 (1 H, d, JH1, H2 1.7 Hz, H-1),
in DEPTCP, ꢀCH CH ꢀ), 84.01 (1 C positive
2
2
5
7
.53 (1 H, s, Ph CH), 6.05 (1 H, s, PhCH),
2
in DEPTCP, Ph CH), 126.88, 127.54, 128.41
13
2
.2–7.4 (15 H, m, Ar H). C NMR (CDCl ):
3
(
4 C, 2 C, 4 C, all positive in DEPTCP, Ar
l 55.29 (ꢀOCH ), 62.36 (C-3), 69.00 (C-2),
3
C-2 and C-6, C-4, C-3 and C-5), 141.82 (2 C,
7
(
1
1
2.75 (C-5), 76.79 (C-4), 81.84 (C-6), 83.78
disappear in DEPTCP, Ar C-1). MS: 228.1
C-1), 99.88 (Ph CH), 101.37 (PhCH), 126.08,
+
2
(
50%) M ; 183.1 (8%), Ph CHO; 67.1 (100%)
2
27.09, 127.20, 127.63, 128.11, 128.19, 128.45,
28.97 (Ar C-2 to C-6), 137.28 (PhCH Ar
Ph CH. Anal. Calcd. for C H O : C, 78.9;
2
15 16
2
H, 7.1. Found: C, 78.5; H, 7.1.
Reaction of diazodiphenylmethane and tin(II)
chloride with methyl 4,6-O-benzylidene-h-
glucopyranoside.—Methyl 4,6-O-benzylidene-
a- -glucopyranoside (1.00 g, 3.54 mmol) and
C-1), 142.06, 142.33 (Ph C Ar C-1 conform-
2
ers). Anal. Calcd for C H O : C, 72.3; H,
2
7
28
6
D
-
6
.3. Found: C, 72.39; H, 6.28.
Methyl 4,6-O-benzylidene-2-O-(3,5-dinitro-
D
benzoyl) - 3 - O - diphenylmethyl - h -
D
- gluco-
tin(II) chloride (0.106 g, 0.559 mmol) were
dissolved in 1,2-dimethoxyethane (180 mL).
Diazodiphenylmethane (1.38 g, 7.10 mmol)
was then added, and a drying tube was fitted
onto the flask. After about 4 h the red color
had disappeared, but a TLC examination (3:2
hexane–EtOAc) showed a substantial amount
of unreacted diol. More diazodiphenyl-
methane (1.00 g 5.15 mmol) was added and
the reaction was left stirring overnight. The
ether products were isolated from a column of
silica gel using a gradient of 95:5–3:2 hexane–
EtOAc.
pyranoside.—Methyl
O-diphenylmethyl-a-
4,6-O-benzylidene-3-
-glucopyranoside (300
D
mg, 0.669 mmol) was treated with triethyl-
amine (0.132 mL, 1.02 mmol) and 3,5-dinitro-
benzoyl chloride (220 mg, 0.954 mmol) in
CH Cl (5 mL). The excess acid chloride was
2
2
quenched with silica gel (1.5 g), and the
product was purified on a silica gel column
using hexane–EtOAc as eluent to give pure
2-(3,5-dinitrobenzoyl ester) (300 mg, 69.8%).
The ester was recrystallized from heptane–
1
EtOAc: mp 228–229 °C. H NMR (CDCl ): l
3
3.37 (3 H, s, ꢀOCH ), 3.8–3.9 (3 H, m, H-4,
3