10.1002/ejoc.201601639
European Journal of Organic Chemistry
FULL PAPER
2
(CH2), 73.1 (CH2), 72.7 (CH2), 69.3 (CH2×2), 65.1 (CH2, JCP = 5.8 Hz); 31
P
EtOAc/hexanes = 30/70 to give the desired product 12 (0.26 g, 74%) as a
colorless oil. Only major isomer was reported. [α]26D48.99 (c = 0.77,
CHCl3); IR(neat) 3492 (OH), 3088, 3063, 3031, 2881, 1957, 1879, 1815,
1730, 1606, 1586, 1497, 1454, 1389, 1336, 1358, 1259, 1236, 1208, 1087,
1045, 1027, 964, 910, 887, 816, 736, 697, 606 cm1; 1H NMR (300 MHz,
CDCl3) δ 7.407.28 (m, 15H), 4.72 (d, J = 11.7 Hz, 1H), 4.65 (d, J = 11.4
Hz, 2H), 4.64 (d, J = 10.8 Hz, 2H), 4.54 (d, J = 12 Hz, 1H), 4.46 (s, 1H),
4.14 (d, J = 10.2 Hz, 1H), 4.10 (s, 2H), 3.62 (d, J = 10.8 Hz, 1H), 3.60 (d,
J = 10.8 Hz, 1H); 13C NMR (75 MHz, CDCl3) δ 138.0 (C), 137.9 (C), 137.6
(C), 137.5 (C), 137.4 (C), 128.4 (CH×2), 128.3 (CH) ,127.9 (CH), 127.8
(CH), 127.7 (CH), 127.6 (CH), 104.6 (C, major), 102.4 (C, minor), 82.1
(CH), 77.9 (CH), 77.1 (CH), 76.6 (CH), 73.8 (CH2), 73.5 (CH2), 73.2 (CH2),
72.7 (CH2), 72.5 (CH2), 72.2 (CH2), 71.7 (CH2), 70.7 (CH2), 69.0 (CH2);
HRMS (ESI) : m/z calcd for C2 6 H2 8 O5 Na [M+Na]+ : 443.1829;
found: 443.1822.
NMR (120 MHz, CDCl3) δ0.911(s), HRMS (ESI) : m/z calcd for
C4 0 H4 2 O8 P [M+H]+ : 681.2612; found: 681.2611.
1,3,4-O-Tribenzy-5-O-trityl-D-lyxitol (10)
To a solution of compound 7 (0.36 g, 0.85 mmol), 4-dimethylaminopyridine
(0.10 g, 0.85 mmol), and trityl chloride (0.71 g, 2.56 mmol) in DCM (8.53
mL) was added triethylamine (0.45 mL, 3.41 mmol). The reaction mixture
was stirred at room temperature for 8 h and then worked up by addition of
MeOH (1 mL). The resulting mixture was diluted with EtOAc (100 mL), and
washed with 1 N HCl (30 mL), saturated NaHCO3(aq) (30 mL), water (30
mL), and brine (30 mL). The organic layer was dried over MgSO4 and
concentrated to give a crude product, which was purified by flash
chromatography with the eluent of EtOAc/hexanes = 15/85 to give the
desired product 10 (0.41 g, 87%) as a yellow oil. [α]26D97.16 (c = 0.97,
CHCl3); IR(neat) 3488 (OH) ,3088, 3061, 3032, 2921, 2868, 2320, 1958,
1877, 1815, 1598, 1492, 1479, 1449, 1396, 1365, 1327, 1214, 1181, 1155,
1090, 1073, 1051, 1028, 1002, 942, 900, 821, 776, 764, 745, 735, 696,
678, 643,632, 619 cm1; 1H NMR (300 MHz, CDCl3) δ 7.527.45 (m, 6H),
7.397.19 (m, 22H), 7.046.98 (m, 2H), 4.76 (d, J = 11.4 Hz, 1H), two d
overlapped at 4.58 (d, J = 11.1 Hz, 1H) and 4.55 (d, J = 12.0 Hz, 1H), 4.47
(d, J = 11.4 Hz, 2H), 4.38 (d, J = 10.8 Hz, 1H), 4.11 (q, J = 6.3 Hz, 1H),
3.91 (dd, J = 7.2, 1.8 Hz, 1H), 3.83 (m, 1H), 3.583.47 (m, 3H), 3.29 (dd,
J = 10.2, 4.5 Hz, 1H), 2.75 (d, J = 6.6 Hz, 1H, OH); 13C NMR (75 MHz,
CDCl3) δ 143.9 (C), 138.1 (C), 137.9 (C), 128.7 (CH), 128.4 (CH), 128.3
(CH), 128.2 (CH), 127.9 (CH), 127.7 (CH), 127.0 (CH), 86.8 (C), 78.6 (CH),
77.2 (CH), 73.7 (CH2), 73.3 (CH2), 72.9 (CH2), 71.2 (CH2), 69.5 (CH), 62.8
(CH2); HRMS (ESI) : m/z calcd for C4 5 H4 4O5 Na [M+Na]+ :
687.3081 ; found: 687.3077; EA: calcd for C4 5H4 4 O5: C,
81.30; H, 6.67; found: C, 80.70; H, 7.25.
2,3,5-O-Tribenzyl-D-arabinose (14)
To a solution of compound 1321 (3.10 g, 7.14 mmol) in acetic acid (43.93
mL) was added 3 M sulfuric acid (11 mL) . The reaction mixture was heated
o
to 100 C for 30 min and then cooled to room temperature. The solution
was neutralized with saturated NaHCO3 (aq) and then extracted with DCM
(150 mL). The organic layer was washed with water (50 mL), brine (50 mL).
The organic layer was dried over MgSO4 and concentrated to give a crude
product, which was purified by flash chromatography with the eluent of
EtOAc/hexanes = 30/70 to give the desired product 14 (2.36 g, 82%) as a
yellow oil. A diastereomeric mixture of products (major / minor = 1 / 0.35)
was obtained. IR(neat) 3418 (OH), 3088, 3064, 3031, 2920, 2867, 1955,
1877, 1814, 1741, 1589, 1496, 1455, 1366, 1208, 1090, 1074, 1027, 958,
909, 822, 737, 698, 617, 609 cm1; 1H NMR (300 MHz, CDCl3) δ 7.417.28
(m, 15H), 5.44 (d, J = 7.2 Hz, 1H, minor), 5.37 (dd, J = 9.9, 4.5 Hz, 1H,
major), 4.69 (d, J = 11.4 Hz, 1H, minor), 4.664.51 (m, 6H), 4.21 (t, J = 4.8
Hz, 1H, major), 4.15 (t, J = 4.2 Hz, 1H, major), 4.083.96 (m, 2H),
3.663.52 (m, 2H); 13C NMR (75 MHz, CDCl3) δ 137.8 (C), 137.6 (C), 137.3
(C), 137.2 (C), 128.3 (CH), 128.2 (CH), 127.9 (CH), 127.7 (CHx2), 127.6
(CH), 127.5 (CH), 100.8 (CH, major), 95.9 (CH, major), 86.9 (CH, major),
83.8 (CH, minor), 82.7 (CH, major), 81.8 (CH, minor), 81.3 (CH, major),
80.2 (CH, minor), 73.3 (CH2, minor), 73.1 (CH2, major), 72.0 (CH2, minor),
71.8 (CH2, major), 71.5 (CH2, minor), 70.5 (CH2, minor), 69.9 (CH2, major);
HRMS (ESI) : m/z calcd for C2 6 H2 8 O5 Na [M+Na]+ :443.1829;
found: 443.1824.
1,3,4-O-Tribenzyl-5-O-trityl-D-erythro-pentulose (11)
To a solution of compound 10 (0.60 g, 0.90 mmol) in DCM (9 mL) was
added a solution of Dess-Matin periodinane (5.42 mmol) in DCM (3.09 mL,
15 wt.%). The reaction mixture was stirred for 2 h at room temperature,
followed by addition of saturate Na2S2O3(aq) (2 mL) and saturate
NaHCO3(aq) (2 mL). The reaction mixture was stirred until both layers
became clear, and then diluted with ether (100 mL). The organic layer was
washed with water (30×2 mL), brine (30 mL). dried over MgSO4, and
concentrated to give a crude product, which was purified by flash
chromatography with the eluent of EtOAc/hexanes =15/85 to give the
desired product 11 (0.6 g, 99%) as a colorless oil. [α]26D14.31 (c = 0.87,
CHCl3) ; IR(neat) 3087, 3062, 3031, 2871, 2249, 1957, 1813, 1733 (C=O),
1597, 1493, 1450, 1371, 1319, 1244, 1212, 1153, 1090, 1076, 1028, 1002,
2,3,5-O-Tribenzyl-D-arabinitol (15)
To a cooled solution of compound 14 (2.36 g, 4.19 mmol) in EtOH (28.1
mL) was added potionwise of sodium borohydride (0.49 g, 12.9 mmol) at
0oC. After stirring at room temperature for 5 h, the pH of the reaction
mixture was adjusted to 45 by dropweise addition of acetic acid. The
resulting mixture was concentrated and then diluted with EtOAc (120 mL).
The organic layer was washed with water (40×2 mL), brine (40 mL). The
organic layer was dried over MgSO4 and concentrated to give a crude
product, which was purified by flash chromatography with the eluent of
EtOAc/hexanes = 40/60 to give the desired product 15 (2.30 g, 97%).
[α]26D+1.64 (C=0.65, CHCl3); IR (neat) 3409 (OH), 3088, 3063, 3031, 2880,
1955, 1879, 1814, 1605, 1586, 1496, 1454, 1398, 1352, 1238, 1209, 1088,
1069, 1027, 911, 819, 735, 696, 601 cm1; 1H NMR (300 MHz, CDCl3) δ
7.437.26 (m, 15H), 4.69 (d, J = 11.7 Hz, 1H), 4.64 (d, J = 11.4 Hz, 2H),
4.60 (d, J = 11.4 Hz, 1H), 4.89 (d, J = 12.6 Hz, 1H), 4.55 (d, J = 12.0 Hz,
908, 849, 819, 729, 696, 647, 632, 619, 604 cm1 1H NMR (300 MHz,
;
CDCl3) δ 7.467.40 (m, 6H), 7.357.21 (m, 22H), 7.147.09 (m, 2H), 4.62
(d, J = 11.4 Hz, 1H), 4.514.43 (m, 4H), 4.39 (d, J = 11.1 Hz, 1H),
4.334.14 (m, 3H) , 3.96 (q, J = 5.0 Hz 1H), 3.40 (dd, J = 10.2, 4.8 Hz, 1H,
H5a), 3.33 (dd, J = 10.2, 5.1 Hz, 1H, H5b); 13C NMR (75 MHz CDCl3), δ
207.0 (C), 143.7 (C) , 137.8 (C), 137.3 (C), 137.1 (C), 128.7 (CH), 128.3
(CH), 127.9 (CH), 127.8 (CH), 127.7 (CH), 127.0 (CH), 87.1 (C), 81.6 (CH),
79.4 (CH), 74.1 (CH2), 73.1 (CH2), 73.0 (CH2), 72.6 (CH2), 62.2 (CH2);
HRMS (ESI) : m/z calcd for C4 5 H4 2O5 Na [M+Na]+ : 685.2924 ;
found: 685.2916.
1,3,4-Tri-O-benzyl- D-erythro-pentulofuranose (12)
1H) 4.06 (br s, 1H), 3.833.66 (m, 6H), 3.24 (br s, OH) 2.66 (br s, OH); 13
C
To a solution of compound 11 (0.55 g, 0.83 mmol) in a co-solvent system
(ether/formic acid, v/v = 1/1, 8.84 mL). The reaction mixture was stirred at
room temperature for 15 min. The solution was diluted with ether and
neutralized with saturated NaHCO3(aq) until the pH was 7. The organic layer
was washed with water, brine, and concentrated to give a crude product,
which was purified by flash chromatography with the eluent of
NMR (75 MHz, CDCl3) δ 137.8 (C), 137.7 (C), 128.2 (CH), 128.0 (CH),
127.9 (CH), 127.7 (CH2), 127.6 (CH), 79.3 (CH), 78.2 (CH) , 73.6 (CH2),
73.2 (CH2), 72.6 (CH2), 70.9 (CH2), 70.3 (CH), 61.1 (CH2); HRMS (ESI) :
m/z calcd for C2 6 H3 1O5 [M+H]+ : 423.2166; found:
423.2161; EA: calcd for C2 6 H30 O5: C, 73.91; H, 7.16;
found: C, 73.64; H, 7.32.
This article is protected by copyright. All rights reserved.