T. Nishiyama et al. / Tetrahedron: Asymmetry 20 (2009) 230–234
233
(m, 5H, –Ph); 13C NMR (100 MHz, CDCl3): d 25.5, 27.8, 53.6, 62.6,
67.1, 72.7, 77.3, 78.8, 109.3, 118.4, 128.1(2C), 128.3, 128.6(2C),
133.5, 136.1, 157.1; IR (CHCl3): 3435, 3028, 3018, 2991, 2939,
2412, 1716, 1602, 1506, 1456, 1429, 1375, 1319, 1261, 1244,
1228, 1213, 1201 cmꢀ1; MS FAB(+) m/z: 352 (M++H); HRMS calcd
for C18H26NO6 (M++H): 352.1760, found: 352.1755. Anal. Calcd
for C18H25NO6: C, 61.52; H, 7.17; N, 3.99. Found: C, 61.51; H,
7.24; N, 3.97.
The residue was used for further reactions without any purifica-
tion. Pyridine (5.0 mL), acetic anhydride (2.5 mL), and a catalytic
amount of N,N-dimethyl-p-aminopyridine were added to a solu-
tion of a partial moiety of the residue (420 mg), and the mixture
was stirred at room temperature for 25 min. The reaction mixture
was poured into ice water and extracted with ethyl acetate. The or-
ganic layer was washed with a saturated solution of sodium chlo-
ride, dried over sodium sulfate, and condensed in vacuo. The
residue was purified by silica gel column chromatography (n-hex-
ane/ethyl acetate = 2:1) to afford 14 (587 mg, 97%) as a colorless
4.3. (2S,3R,4S,5S)-2-N-Carboxybenzylamido-3-hydroxy-2,3/4,5-
O,N-diisopropyriden-6-heptenyl 1-O-p-toluenesulfonylate 12
oil. ½a 2D7
ꢁ
¼ þ22:6 (c 0.95, CHCl3); 1H NMR (400 MHz,CDCl3): d
1.12 (d, J = 7.2 Hz, 3H), 2.07, 2.08, 2.10 (each s, 3H), 4.05 (m, 1H),
5.05–5.13 (m, 2H), 5.08, 5.12 (each d, AB type, J = 12.0 Hz, 1H,
CH2-Ph), 5.25 (dd, J = 7.6, 3.8 Hz, 1H), 5.30 (d, J = 16.8 Hz, 1H,
CHH=CH-), 5.31 (d, J = 11.0 Hz, 1H, CHH=CH-), 5.43 (dd, J = 6.8,
3.8 Hz, 1H, CHH@CH), 5.84 (ddd, J = 16.8, 11.0, 6.8 Hz, 1H,
CH@CH2), 7.29–7.38 (m, 5H, –Ph); 13C NMR (100 MHz, CDCl3): d
15.4, 20.8(2C), 20.9, 47.1, 66.7, 71.3, 73.1, 73.2, 120, 128.1(3C),
128.5(2C), 131.0, 136.4, 155.4, 169.9, 170.0, 170.1; IR (CHCl3):
3026, 3014, 1744, 1602, 1510, 1456, 1429, 1371, 1240 cmꢀ1; MS
FAB(+) m/z: 444 (M++Na); HRMS calcd for C21H27NO8Na (M++Na):
444.1634, found: 444.1638.
Triethylamine (86
lL), p-toluenesulfonyl chloride (58.7 mg,
0.31 mmol), and N,N-dimethyl-p-aminopyridine were added to a
solution of 10 (43.3 mg, 0.123 mmol) in dichloromethane
(3.0 mL), and the mixture was stirred for 14 h at room tempera-
ture. The reaction mixture was poured into ice water and extracted
with ethyl acetate. The organic layer was washed with a saturated
aqueous solution of sodium chloride, dried over sodium sulfate,
and condensed in vacuo. The residue was purified by silica gel col-
umn chromatography (n-hexane/ethyl acetate = 2:1) to afford 11
(78.7 mg) as a colorless oil. Next, without further purification,
2,2-dimethoxypropane (46 lL, 0.37 mmol) and a catalytic amount
of p-toluenesulfonic acid monohydrate were added to a solution of
11 (78.7 mg) in toluene (3.0 mL), and the reaction mixture was
stirred for 45 min at 50 °C and for another 20 min at 80 °C. The
mixture was poured into a saturated aqueous solution of sodium
bicarbonate and extracted with ethyl acetate. The organic layer
was washed with a saturated aqueous solution of sodium chloride,
dried over sodium sulfate, and condensed in vacuo. The residue
was purified by silica gel column chromatography (n-hexane: ethyl
acetate = 5:1) to afford 12 (59.3 mg, 88% overall yield in two steps)
4.5. (2S,3R,4S,5S)-2-N-Carboxybenzylamido-3,4-diacetoxy-6-
heptene 15
Ammonium formate (7.4 mg, 0.12 mmol) and tetrakis(triphen-
ylphosphine) palladium (20.4 mg, 0.02 mmol) were added to a
solution of 14 (24.8 mg, 0.059 mmol) in tetrahydrofuran (2.0 mL),
and the mixture was stirred for 15 h at reflux. The reaction mixture
was poured into ice water and extracted with ethyl acetate. The or-
ganic layer was washed with a saturated aqueous solution of so-
dium chloride, dried over sodium sulfate, and condensed in
vacuo. The residue was purified by silica gel column chromatogra-
phy (n-hexane/ethyl acetate = 2:1) to afford 15 (105 mg, 88%) as a
as
a
colorless oil.
½
a 2D6
ꢁ
¼ ꢀ2:6 (c 0.94, CHCl3); 1H NMR
(400 MHz,CDCl3, major conformer): d 1.28, 1.41 (each s, 3H), 1.47
(s, 3H, –O–C(CH3)2–N–), 1.55 (s, 3H, –O–C(CH3)2–N–), 2.42 (s,
3H), 4.00 (dd, J = 9.8, 5.6 Hz, 1H), 4.08 (m, 1H), 4.17–4.24 (m,
2H), 4.28 (dd, J = 9.8, 4.4 Hz, 1H), 4.68 (t, J = 6.0 Hz, 1H), 4.90 (d,
A part of AB, J = 12.0 Hz, 1H, –CHHPh), 5.04 (d, B part of AB,
J = 12.0 Hz, 1H, –CHHPh), 5.23 (dt, J = 10.8, 1.6 Hz, 1H, CHH@CH),
5.40 (dt, J = 17.2, 1.6 Hz, 1H, CHH@CH), 5.87 (ddd, J = 17.2, 10.8,
6.0 Hz, 1H, CH2@CH), 7.24–7.38 (m, 7H), 7.72 (d, J = 8.0 Hz, 2H.);
13C NMR (100 MHz, CDCl3, maj. conf.): d 21.6, 23.2, 25.1, 25.6,
27.6, 57.2, 66.5, 67.0, 73.3, 74.6, 78.3, 95.0, 109.2, 117.5, 127.9,
128.1(2C), 128.2(2C), 128.5(2C), 129.8(2C), 132.6, 132.8, 136.0,
144.8, 151.7; IR (CHCl3): 3022, 3010, 1705, 1599, 1410, 1381,
1352, 1236, 1222 cmꢀ1; MS FAB(+) m/z: 568 (M++Na); HRMS calcd
for C28H35NO8SNa (M++Na): 568.1981, found: 568.1984.
pale yellow oil.
½
a 2D5
ꢁ
¼ þ24:0 (c 1.17, CHCl3); 1H NMR
(400 MHz,CDCl3): d 1.14 (d, J = 6.8 Hz, 3H), 2.04, 2.09 (each s,
3H), 2.31 (m, 1H), 2.47 (m, 1H), 4.04 (m, 1H), 4.96 (br d, 8.8 Hz,
1H, –NH), 5.00–5.14 (m, 6H), 5.70 (ddt, J = 16.8, 10.0, 7.0 Hz, 1H,
–CH@CH2) 7.29–7.39 (m, 5H); 13C NMR (100 MHz, CDCl3): d 16.3,
20.8, 20.9, 34.4, 46.7, 66.8, 71.3, 75.5, 118.2, 128.0(2C), 128.1,
128.5(2C), 132.9, 136.3, 155.5, 170.4(2C); IR (CHCl3): 3431, 3039,
3022, 3012, 1732, 1645, 1603, 1510, 1456, 1435, 1371, 1238,
1228, 1215, 1207 cmꢀ1; MS FAB(+) m/z: 386 (M++Na); HRMS calcd
for C19H25NO6Na (M++Na): 386.1580, found: 386.1576.
4.6. 5-N-Carboxybenzylamido-5,6-dideoxy-3,4-diacetoxy-
D-
allo-iminopyranoside (ꢀ)-16
4.4. (2S,3R,4S,5S)-2-N-Carboxybenzylamido-3,4,5-triacetoxy-6-
heptene 14
Ozone gas was bubbled into a solution of compound 15
(109 mg, 0.30 mmol) in dichloromethane (35 ml) at ꢀ78 °C until
a pale purple color was maintained in the solution. After the excess
ozone was removed from the reaction mixture by bubbling nitro-
gen gas, triphenylphosphine (158 mg, 0.60 mmol) was added, and
the mixture was stirred overnight at room temperature. The organ-
ic solvent was evaporated off, and the residue was purified by silica
gel column chromatography (n-hexane/ethyl acetate = 2:1) to af-
A solution of 2.0 M of lithium borohydride in tetrahydrofuran
(0.12 mL, 0.24 mmol) was added to a solution of 12 (22.0 mg,
0.04 mmol) in dimethyl sulfoxide (2.0 mL), and the mixture was
stirred for 17 h at 100 °C. After another solution of lithium borohy-
dride in tetrahydrofuran (0.06 mL, 0.12 mmol) was added and stir-
red for another 1 h at the same temperature as above, the reaction
mixture was poured into ice water and extracted with diethyl
ether. The organic layer was washed with a saturated aqueous
solution of sodium chloride, dried over sodium sulfate, and con-
densed in vacuo. The residue was purified by preparative silica
gel thin layer chromatography (n-hexane/ethyl acetate = 2:1) to af-
ford 13 (10.2 mg, 67%). Next, Dowex 50 W (X4, H+-form) was
added to a solution of 13 (537 mg, 1.43 mmol) in methanol
(20.0 mL), and the mixture was stirred for 14 h at 65 °C. The reac-
tion mixture was filtered, and the filtrate was condensed in vacuo.
ford (ꢀ)-16 (105 mg, 95%) as a colorless oil. ½a D21
¼ ꢀ26:4 (c 1.24,
ꢁ
CHCl3); 1H NMR (400 MHz,CDCl3): d 1.42 (d, J = 7.2 Hz, 3H), 2.02,
2.06 (each s, 3H), 1.97–2.04 (br, 1H), 2.15 (td, J = 12.8, 4.4 Hz,
1H), 3.15 (br, 1H, OH), 4.34 (br, 1H), 5.12–5.26 (m, 3H), 5.53
(ddd, J = 12.8, 4.8, 2.8 Hz, 1H), 5.99 (br s, 1H), 7.29–7.39 (m, 5H,
–Ph); 13C NMR (100 MHz, CDCl3): d 19.3, 20.9, 21.0, 30.1, 52.5,
63.9, 67.7, 70.2, 76.3, 127.9, 128.3(2C), 128.6(2C), 136.0, 152.3,
170.2(2C); IR (CHCl3): 3678, 3595, 3017, 1740, 1693, 1602, 1499,
1417, 1369, 1334, 1242, 1220, 1203 cmꢀ1; MS FAB(+) m/z: 388