112
A.A.-H. Abdel-Rahman et al. / Carbohydrate Research 315 (1999) 106–116
(8:2 CH2Cl2–MeOH); [h]2D0 +28.5° (c 1,
(3×100 mL) with CH2Cl2. The solvent was
removed in vacuo (25 °C) to leave a syrup
whose TLC showed two spots. Separation was
carried out by FC using 5:1 toluene–EtOAc
to give 13 (0.197 g, 35%) and 14 (0.410 g,
60%).
1
CHCl3); H NMR (600 MHz, DMSO-d6): l
1.77–1.81 (m, 2 H, CH2), 2.98–3.03 (m, 2 H,
CH2), 3.09–3.11 (brs, 1 H, OH), 3.28–3.32
(m, 5 H, 3 OH, H2O), 3.37–3.38 (m, 1 H,
H-5%), 3.64–3.66 (m, 1 H, H-6%a), 3.84–3.87
(m, 1 H, H-6%b), 4.53 (brs, 1 H, H-1%), 4.83–
4.84 (m, 2 H, H-2%, 4%), 4.94 (brs, 1 H, H-3%),
5.50 (brs, 1 H, NH), 6.48 (t, 1 H, J 7.2 Hz,
Ar-H), 6.55 (d, 2 H, J 7.8 Hz, Ar-H), 7.04 (t,
1-C-(2,3,5-Tri-O-acetyl-h- -arabinofura-
D
nosyl)carbonitrile (13).—An oil; Rf 0.59 (1:1
EtOAc–toluene); [h]2D0 +30.5° (c 1, CHCl3);
1H NMR (250 MHz, CDCl3): l 2.11 (s, 3 H,
OAc), 2.15 (s, 3 H, OAc), 2.16 (s, 3 H, OAc),
13
2 H, J 7.8 Hz, Ar-H); C NMR (150.9 MHz,
4.24 (dd, 2 H, J4,
7.2 Hz, J5,
12.8 Hz,
H-5%), 4.38 (m, 2 H,5H% -4, 5), 4.85 (5d% , 1 H, J1,2
0.6 Hz, H-1), 5.13 (t, 1 H, J2, 3 2.3 Hz, H-2),
5.36 (t, 1 H, J3, 4 1.3 Hz, H-3); 13C NMR (62.9
MHz, CDCl3): l 20.20 (OAc), 20.34 (2 OAc),
62.15 (C-5), 70.72 (C-3), 76.64 (C-2), 79.55
(C-4), 82.77 (C-1), 114.95 (CN), 169.02,
169.42, 170.08 (3 OAc); EIMS: m/z (%): 285
(M, 3), 243 (6), 225 (9), 45 (100). Anal. Calcd
for C12H15NO7: C, 50.52; H, 5.30; N, 4.91.
Found: C, 50.22; H, 5.18; N, 4.77.
DMSO-d6): l 23.82 (C-2), 40.02 (C-1), 61.62
(C-6%), 70.89 (C-5%), 71.22 (C-4%), 73.79 (C-2%,
3%), 73.82 (C-1%), 111.93, 115.31, 128.81, 141.53
(Ar-C); FABMS: m/z (%): 284 (MH, 20).
Anal. Calcd for C14H21NO5: C, 59.35; H, 7.47;
N, 4.94. Found: C, 59.02; H, 7.13; N, 4.60.
1-C-(h-
anhydro-
D
-Arabinofuranosyl)methanal (2,5-
D
-mannose) oxime (12).—Hydroxyl-
amine hydrochloride (2.50 g, 36 mmol) and
anhydrous sodium acetate (2.84 g, 15.2 mmol)
were dissolved in absolute EtOH (50.0 mL)
with stirring for 1 h. The mixture was filtered,
1-C-(2,3,5-Tri-O-acetyl-h- -arabinofur-
D
anosyl)methanal oxime acetate (14).—An oil;
and the filtrate was added to 2,5-anhydro- -
D
Rf 0.48 (1:1 EtOAc–toluene); [h]2D0 +4.3° (c 1,
mannose (11) (2.50 g, 39.0 mmol), and the
stirring was continued for 1.5 h (TLC). The
solvent was removed in vacuo (30 °C), and the
residue was purified by FC using 5:1 EtOAc–
MeOH to give a pale yellowish green syrup
(2.11 g, 77.0%) as a mixture of E and Z
isomers. Rf 0.45 (1:1 EtOAc–MeOH); [h]D20
1
CHCl3); H NMR (250 MHz, CDCl3): l 2.11
(s, 6 H, 2 OAc), 2.13 (s, 3 H, OAc), 2.18 (s, 3
H, OAc), 4.24–4.33 (m, 3 H, H-4, 5, 5%), 4.80
(dd, 1 H, J1, 2 0.6, J1, 1% 6.5 Hz, H-1), 5.21 (t,
1 H, J2, 3 2.8 Hz, H-2), 5.37 (dd, 1 H, J2, 3 2.7,
J3, 4 3.8 Hz, H-3), 7.75 (d, 1 H, J1, 1% 6.4 Hz,
CHꢀN); 13C NMR (62.9 MHz, CDCl3): l
19.00, 20.34, 20.37, 20.43 (4 OAc), 62.90 (C-
5), 77.62 (C-3), 78.61 (C-2), 79.48 (C-4), 81.41
(C-1), 154.26 (CHꢀN), 167.72, 169.33, 169.46,
170.19 (4 OAc); EIMS: m/z (%): 345 (M, 35),
303 (47), 243 (42), 230 (9). Anal. Calcd for
C14H19NO9: C, 48.69; H, 5.54; N, 4.05. Found:
C, 48.41; H, 5.33; N, 3.76.
1
−1.5° (c 1, CHCl3); H NMR (250 MHz,
DMSO-d6): l 1.91–4.15 (4 m, 8 H, 3 OH,
furanosyl-H); major isomer: l 7.28 (d, 0.7 H,
J 7.8 Hz, CHꢀN), 10.83 (s, 0.7 H, ꢀNꢀOH);
minor isomer: l 6.67 (d, 0.3 H, J 7.8 Hz,
CHꢀN), 10.91 (brs, 0.3 H, ꢀNꢀOH); 13C
NMR (62.9 MHz, DMSO-d6): major isomer:
l 61.78 (C-5), 77.13 (C-3), 79.88 (C-2), 80.94
(C-4), 84.73 (C-1), 149.23 (CHꢀN); minor iso-
mer: l 62.04 (C-5), 77.65 (C-3), 79.08 (C-2),
80.40 (C-4), 86.84 (C-1), 151.27 (CHꢀN);
EIMS: m/z (%): 177 (M, 6), 159 (55), 146 (28).
1-C-(2,3,5-Tri-O-acetyl-h- -arabinofur-
D
anosyl)methylamine (15).—Compound 14
(0.33 g, 0.96 mmol) was dissolved in 1:1 diox-
ane–MeOH (26.0 mL), and 8–10 drops of
water were added. The stirred mixture was
treated with Pd(OH)2/C (35.0%, 0.12 g) and
then kept under hydrogen with continued stir-
ring at rt for 4 h (TLC). The mixture was
diluted with MeOH (100 mL), filtered through
Celite, and washed well with MeOH. [Caution:
Pd(OH)2/C mixtures with MeOH are ex-
tremely pyrophoric.] The solvent was removed
under reduced pressure (35 °C) to give a red-
Acetylation of 1-C-(h- -arabinofuranosyl)-
D
methanal oxime.—The oxime derivative 12
(0.35 g, 1.97 mmol) was dissolved in pyridine
(3.00 mL) and then cooled in an ice-bath.
Acetic anhydride (1.53 mL) was added drop-
wise with stirring at −10 °C, and the mixture
was then kept at −5 °C for 24 h. It was
poured onto crushed ice and then extracted