S. Abo et al. / Carbohydrate Research 322 (1999) 201–208
203
(4×OC(O)Me), 23.3 (NC(O)Me), 26.1 (C-3%),
28.6 (C(CH3)3), 28.8 (C-4%), 29.1 (C-2%), 29.5
(C-1%), 38.3 (C-3), 41.1 (C-5%), 49.6 (C-5), 53.1
(CO2Me), 62.5 (C-9), 67.7, 68.9 (C-7/C-8),
69.9 (C-4), 74.3 (C-6), 83.4 (C-2), 156.2
(NC(O)O), 168.7 (C-1), 170.4, 170.8, 171.1
(4×OC(O)Me/NC(O)Me); LRMS: m/z 693
[(M+1)+, 10%], 593(40), 414(44).
(25 mL), dried (Na2SO4) and concentrated
under reduced pressure. Column chromatog-
raphy on silica gel (1:2 EtOAc–hexane, Rf
0.63) gave 4 (0.34 g, 52%) as an amorphous
pink mass; mp 26–27 °C (dec); wmax (NaCl)
1
3368, 2984, 2940, 1688 cm−1; H NMR (300
MHz; CDCl3): l 1.41 (s, 9 H, C(CH3)3), 1.41–
1.53 (m, 4 H, H-4, 3), 1.84 (p, 2 H, J2,1 6.5 Hz,
H-2), 3.09 (q, 2 H, J1,2 6.5 Hz, H-1), 3.38 (t, 2
H, J5,4 6.8 Hz, H-5), 4.63 (bs, 1 H, NH); 13C
NMR (75.5 MHz; CDCl3): l 25.5 (C-3), 28.5
(C(CH3)3), 29.4 (C-4), 32.4 (C-2), 33.8 (C-5),
40.4 (C-1), 79.2 (C(CH3)3), 156.1 (NC(O)O);
LRMS: m/z 268 [(81Br M+1)+, 38%], 266
[(79Br M+1)+, 39%], 212 (43), 210 (47), 192
(32), 168 (15). HRMS (positive-ion): Calcd for
C10H21NO739Br 266.07556; Found: 266.07574.
Anal. Calcd for C30H48N2O14S·H2O: C,
50.69; H, 7.09; N, 3.94. Found: C, 50.26; H,
6.76; N, 3.94.
2 - S - (5% - N - tert - butyloxycarbonyl - amino-
pentyl) 5 - acetamido - 2 - thio -
D
- glycero - h - -
D
galacto-2-nonulopyranosidonic acid (6).—
Compound 5 (0.61 g, 0.88 mmol) was treated
with a soln of NaOMe (0.44 mmol) in anhyd
MeOH (12 mL) at rt under N2. After stirring
for 2 h, the MeOH was removed under re-
duced pressure, water (12 mL) added, and the
pH adjusted to 12 with 0.1 M NaOH. After
stirring overnight, the pH of the reaction mix-
ture was adjusted to 7.0–7.5 with Dowex-
50W×8 (H+) resin. After filtration, the
filtrate was lyophilised to afford the target
compound 6 as an amorphous cream solid,
which was in a pure state according to NMR
spectroscopy (0.37 g, 83%); mp 148 °C (dec);
Methyl
aminopentyl) 5 - acetamido - 4,7,8,9 - tetra - O-
acetyl 3,5 - dideoxy - 2 - thio - - glycero - h - -
[2-S-(5%-N-tert-butyloxycarbonyl-
D
D
galacto-2-nonulopyranosid]onate (5).—Methyl
5-acetamido-4,7,8,9-tetra-O-acetyl-2-S-acetyl-
3,5-dideoxy-2-thio-
D
-glycero-a- -galacto-2-
D
nonulopyranosonate (2) (0.7 g, 1.27 mmol)
and 4 (0.34 g, 1.27 mmol) were dissolved in
dry DMF (8 mL) at rt under N2, Et2NH (3.2
mL) was added, and the reaction mixture was
stirred for 3 h at rt. The mixture was concen-
trated under reduced pressure and the residue
was diluted with EtOAc (50 mL) and was
washed with pH 4 buffer (50 mL), water (2×
50 mL), dried (Na2SO4) and evaporated to
dryness under reduced pressure. Column chro-
matography on silica gel (EtOAc, Rf 0.57)
gave 5 (0.71 g, 80%) as an amorphous mass;
mp 61–64 °C; [h]2D8 +23.5° (c 1, CHCl3); wmax
(2:3:1 EtOAc–iPrOH–H2O, Rf 0.72); [h]D28
+
21.7° (c 0.5, H2O); wmax (KBr) 3448, 1616,
1
1366, 1032 cm−1; H NMR (300 MHz; D2O):
l 1.41–1.58 (m, 4 H, H-3%, 4%), 1.50 (s, 9 H,
C(CH3)3), 1.63–1.74 (m, 2 H, H-2%), 1.81 (dd,
1 H, J3a,3e 12.0, J3a,4 11.9 Hz, H-3a), 2.11 (3 H,
s, AcN), 2.64–2.82 (m, 2 H, H-1%), 2.87 (dd, 1
H, J3e,4 4.7 Hz, H-3e), 3.10–3.14 (t, 2 H, J5%,4%
6.6 Hz, H-5%), 3.60–3.81 (m, 4 H, H-4, 6, 7,
1
13
(KBr) 3408, 1740, 1688, 1228, 1030 cm−1; H
9a), 3.84–3.95 (m, 3 H, H-5, 8, 9b); C NMR
NMR (300 MHz; CDCl3): l 1.39−1.59 (m, 6
H, H-2%, 3%, 4%), 1.44 (s, 9 H, C(CH3)3), 1.88 (s,
3 H, AcN), 1.89–2.03 (m, 1 H, H-3a), 2.03,
2.04, 2.15, 2.17 (4×s, 12 H, 4×AcO), 2.49–
2.59 (m, 1 H, H-1a%), 2.67–2.79 (m, 2 H,
H-1b%, 3e), 3.11 (q, 2 H, J5%,4% 6.2 Hz, H-5%),
3.80 (s, 3 H, CO2Me), 3.83 (dd, 1 H, J6,7 2.0
Hz, H-6), 4.02–4.34 (m, 2 H, H-5, 9a), 4.32
(dd, 1 H, J9b,9a 9.9, J9b,8 2.7 Hz, H-9b), 4.76
(bs, 1 H, NHC(O)O), 4.87 (ddd, 1 H, J4,3a
11.0, J4,5 10.5, J4,3e 4.6 Hz, H-4), 5.11 (d, 1 H,
JNH,5 10.0 Hz, NH), 5.31 (dd, 1 H, J7,8 8.6 Hz,
H-7), 5.37 (ddd, 1 H, J8,9a 5.2 Hz, H-8); 13C
NMR (75.5 MHz; CDCl3): l 20.9, 21.0, 21.3
(75.5 MHz; D2O): l 25.2 (NC(O)Me), 28.5
(C-3%), 31.0 (C(CH3)3), 31.6 (C-4%), 32.1 (C-2%),
32.5 (C-1%), 43.1, 44.3 (C-3, 5%), 54.9 (C-5),
65.7 (C-9), 71.3 (C-7*), 71.6 (C-8*), 74.1 (C-
4), 77.9 (C-6*), 83.8 (C(CH3)3), 89.4 (C-2),
161.0 (NC(O)O), 177.2 (C-1), 178.1
(NC(O)Me); LRMS: m/z 533 [(M+Na)+,
33%], 455(31).
2-S-(5%-aminopentyl) 5-acetamido-3,5-dide-
oxy-2-thio-
D
-glycero-h- -galacto-2-nonulo-
D
pyranosidonic acid (1).—Compound 6 (0.25 g,
0.49 mmol) in trifluoroacetic acid (8 mL) was
stirred at rt for 10 min. The reaction mixture
was diluted with toluene and concentrated