1016
R. Csuk et al. / Tetrahedron: Asymmetry 15 (2004) 1013–1017
ethanol (45 mL) and water (50 mL) slowly added. After
standing at 5 ꢁC for 24 h, the crystals were collected and
recrystallized from ethanol/water to yield 5 (34.1 g,
96%). Mp 105–106 ꢁC; RF (ethyl acetate/toluene 5:2)
Stirring was continued at room temperature for another
5 min, after which diethylether (250 ml) was added and
the reaction mixture washed with cold water (2 · 20 mL).
The organic layer was dried over Na2SO4, the solvents
evaporated and the residue subjected to chromatogra-
phy (silica gel, toluene/ethyl acetate 3:1) to afford 7
(1.3 g, 71%). Mp 29–31 ꢁC; RF (toluene/ethyl acetate 3:1)
0.53; ½aꢁ ¼ )16.6 (c 1.0, CHCl3); IR (KBr): m ¼ 3030w,
D
3000w, 2950w, 2920w, 1750s, 1480w, 1380s, 1360s,
1
1350s, 1305m, 1270s, 1255s, 1125m, 1080s; H NMR
(400 MHz, CDCl3): d ¼ 1:32 (t, J ¼ 7:0 Hz, 3H, Me),
1.37 (s, 3H, Me), 1.51 (s, 3H, Me), 3.08 and 3.11 (each s,
each 3H, 2 · Me of OMs), 4.23 and 4.28 (q · AB,
J ¼ 7:1, 10.6 Hz, 2H, CH2), 4.45 (dd, J ¼ 4:7, 11.9 Hz,
1H, 6-HA), 4.46 (dd, J ¼ 2:8, 8.6 Hz, 1H, 4-H), 4.61 (d,
J ¼ 3:5 Hz, 1H, 2-H), 4.69 (dd, J ¼ 2:3, 11.9 Hz, 1H, 6-
HB), 5.11 (ddd, J ¼ 2:3, 4.7, 8.6 Hz, 1H, 5-H), 5.25 (d,
J ¼ 2:8 Hz, 1H, 3-H), 5.92 (d, J ¼ 3:5 Hz, 1H, 1-H); 13C
NMR (50 MHz, CDCl3): d ¼ 14:1 (q, Me), 26.1 (q, Me),
26.7 (q, Me), 37.5 (q, Me of OMs), 38.8 (q, Me of OMs),
64.9 (t, CH2), 68.3 (t, 6-C), 72.7 (d, 4-C) 75.9 (d, 5-C),
77.7 (d, 3-C) 82.9 (d, 2-C), 104.9 (d, 1-C), 112.9 (s, Ci),
153.7 (s, C@O); MS (e.i., 70 eV): m=z (%) ¼ 433 (61), 345
(77), 277 (28), 247 (37), 231 (20), 205 (100), 127 (30), 109
(30); MS (c.i., isobutane): m=z ¼ 391 ([M)58+1]þ);
Anal. Calcd for C14H24O12S (448.47): C, 37.50; H, 5.39;
S, 14.30. Found: C, 37.25; H, 5.52; S, 14.41.
0.53; ½aꢁ ¼ +9.5 (c 3.4, CHCl3); IR (KBr): m ¼ 3447s,
D
2999m, 1752m, 1636s, 1458s, 1376s, 1262s, 1064s,
1
1050s cmꢀ1; H NMR (250 MHz, CDCl3): d ¼ 1:35 (s,
3H, Me), 1.50 (s, 3H, Me), 4.71 (d, J ¼ 3:9 Hz, 1H,
2-H), 4.86 (d, J ¼ 5:9 Hz, 1H, 3-H), 5.20 (t, J ¼ 2:7 Hz,
1H, 5-H), 5.39 (dd, J ¼ 2:7, 5.9 Hz, 1H, 4-H), 5.84 (d,
J ¼ 3:9 Hz, 1H, 1-H), 6.46 (d, J ¼ 2:7 Hz, 1H, 6-H); 13C
NMR (50 MHz, CDCl3): d ¼ 27:2 (q, Me), 27.9 (q, Me),
85.0 (d, 4-C), 85.1 (d, 3-C), 87.7 (d, 2-C), 102.6 (d, 5-C),
105.6 (d, 1-C), 113.0 (s, Ci), 150.5 (d, 6-C); MS (e.i.,
70 eV): m=z (%) ¼ 184 (4), 169 (9), 167 (9), 126 (8), 100
(14), 97 (17), 86 (9), 71 (11), 59 (11), 55 (100); MS (c.i.,
isobutane): m=z ¼ 185 ([M+1]þ); Anal. Calcd for
C9H12O4 (184.19): C, 58.69; H, 6.57. Found: C, 58.61;
H, 6.63.
3.8. 3,6-Anhydro-5-deoxy-1,2-O-isopropylidene-a-D-
erythro-hex-4-enofuranose 8
3.6. 3,6-Anhydro-1,2-O-isopropylidene-5-O-methane-
-glucofuranose 6
sulfonyl-a-
D
A solution of 7 (0.9 g, 4.9 mmol) in dry DMSO con-
taining potassium tert-butoxide (0.2 g, 1.8 mmol) was
stirred for 30 min at 25 ꢁC; work up as described for 7
gave 8 (0.7 g, 77%) as a white solid. Mp 77–88 ꢁC; RF
To a solution of 5 (30.0 g, 67 mmol) in refluxing ethanol
(300 mL) an aq. solution of KOH (N, 75 mL) was added
and refluxing was continued for another 2 h. The mix-
ture was cooled to room temperature, water (600 mL)
then added and the reaction set aside at 5 ꢁC for 3 days.
The crystals were collected and recrystallized from eth-
anol to afford 6 (17.1 g, 91%). Mp 111–112 ꢁC; RF (ethyl
(toluene/ethyl acetate 3:1) 0.51; ½aꢁ ¼ +68 (c 1, CHCl3);
D
IR (KBr): m ¼ 3446s, 2932s, 1759s, 1636m, 1463m,
1
1376m, 1261s, 1165s, 1072s cmꢀ1; H NMR (250 MHz,
CDCl3): d ¼ 1:47 (s, 3H, Me), 1.54 (d, J ¼ 0:9 Hz, 3H,
Me), 4.56 (ddd, J ¼ 2:7, 3.6, 11.2 Hz, 1H, 6-HA), 4.68 (d,
J ¼ 5:2 Hz, 1H, 2-H), 4.77 (ddd, J ¼ 1:4, 4.9 Hz, 1H,
6-HB), 5.01 (ddd, J ¼ 3:3, 3.6, 4.9 Hz, 1H, 3-H), 5.97
(dd, J ¼ 0:9, 5.2 Hz, 1H, 1-H); 13C NMR (50 MHz,
CDCl3): d ¼ 27:9 (q, Me), 28.4 (q, Me), 77.4 (t, 6-C),
82.8 (d, 3-C), 87.8 (d, 2-C), 97.9 (d, 5-C), 111.7 (d, 1-C),
115.8 (s, Ci), 156.0 (s, 4-C); MS (e.i., 70 eV): m=z
(%) ¼ 184 (10), 167 (16), 149 (29), 127 (26), 115 (26), 97
(30), 87 (50), 85 (80), 73 (39), 57 (100); MS (c.i., isobu-
tane): m=z ¼ 185 ([M+1]þ); Anal. Calcd for C9H12O4
(184.19): C, 58.69; H, 6.57; C, 58.62; H, 6.61.
acetate/toluene 5:2) 0.49; ½aꢁ ¼ +58.0 (c 1.5, CHCl3); IR
D
(KBr): m ¼ 3050w, 3020w, 3000w, 2980w, 2960w, 2950w,
2895w, 1390m, 1380m, 1320s, 1270m, 1260m, 1230w,
1210m, 1180s, 1170s, 1120m, 1110m, 1090m, 1070s,
1040s, 1010s cmꢀ1
;
1H NMR (400 MHz, CDCl3):
d ¼ 1:33 (s, 3H, Me), 1.48 (s, 3H, Me), 3.13 (s, 3H, Me
of OMs), 3.81 (dd, J ¼ 7:8, 8.9 Hz, 1H, 6-HA), 4.07 (dd,
J ¼ 6:8, 8.9 Hz, 1H, 6-HB), 4.55 (d, J ¼ 3:8 Hz, 1H, 3-
H), 4.62 (d, J ¼ 3:6 Hz, 1H, 2-H), 4.96 (dd, J ¼ 3:8,
4.2 Hz, 1H, 4-H), 5.04 (ddd, J ¼ 4:2, 6.8, 7.8 Hz, 1H, 5-
H), 5.97 (d, J ¼ 3:6 Hz, 1H, 1-H); 13C NMR (50 MHz,
CDCl3): d ¼ 26:7 (q, Me), 27.3 (q, Me), 38.6 (q, Me of
OMs), 68.7 (t, 6-C), 77.1 (d, 4-C), 80.6 (d, 5-C), 84.7 (d,
3-C), 85.1 (d, 2-C), 107.2 (d, 1-C), 112.9 (s, Ci); MS (e.i.,
70 eV): m=z (%) ¼ 280 (10), 265 (60), 164 (10), 143 (10),
127 100), 115 (11), 97 (11), 85 (53), 79 (24); MS (c.i.,
isobutane): m=z ¼ 281 ([M+1]þ); Anal. Calcd for
C10H16O7S (280.39): C, 42.85; H, 5.75; S, 11.44. Found:
C, 42.68; H, 5.84; S, 11.59.
3.9. (4R,5R) 2,2-Dimethyl-5-[(2R)-3-oxotetrahydro-2-
furanyl]-1,3-dioxolan-4-yl acetate [(1R)-1-O-acetyl-3,6-
anhydro-5-deoxy-1,2-O-isopropylidene-L-threose] 1
A solution of 8 (0.8 g, 4.3 mmol) in abs. dichloro-
methane (25 mL) containing glacial acetic acid (0.4 g,
6.64 mmol) was stirred for 2 h at room temperature. The
solvents were removed under diminished pressure and
the residue subjected to chromatography (silica gel,
toluene/ethyl acetate 15:1) to afford 1 (0.76 g, 72%); an
analytical sample was obtained by recrystallization from
hexane. Mp 80–82 ꢁC; RF ¼ (toluene/ethyl acetate 15:1)
3.7. 3,6-Anhydro-5-deoxy-1,2-O-isopropylidene-a-D-
xylo-hex-5-enofuranose 7
To a solution of 6 (3.5 g, 9.77 mmol) in dry DMSO
(10 mL) at 5 ꢁC, potassium tert-butoxide (1.2 g,
10 mmol) was added in several portions under argon.
0.16; ½aꢁ ¼ +159.8 (c 1.1, CHCl3); IR (KBr): m ¼ 3440w,
D
2995m, 2945m, 1765s, 1740s, 1460w, 1390s, 1370s,
1240s, 1215s, 1170s, 1130s, 1075s, 1040s, 1015s cmꢀ1; 1H