Paper
Organic & Biomolecular Chemistry
rel-(1S,2S,3R,4R,5R)-5-Bromocyclohexane-1,2,3,4-tetrayl
tetraacetate (38)
2353, 1447, 1418, 1341, 1296, 1254, 1196, 1072, 1034, 990, 945,
864, 679, 631; Anal. Calcd for C6H11BrO4: C, 31.74; H, 4.88;
Found: C, 31.57; H, 4.97.
0.15 g, 4%, pale yellow liquid. 1H-NMR (300 MHz, CDCl3)
δ 5.58 (dd, J = 9.5, 2.9 Hz, 1H, H-3), 5.43 (br. dd, J = 3.6, 2.9 Hz,
1H, H-4), 5.38–5.27 (m, 2H, H-1 and H-2), 4.22 (quasi q, J = 4.0
Hz, H-5), 2.40–2.32 (m, 2H, H-6), 2.13 (s, 3H, CH3), 2.043
(s, 3H, CH3), 2.037 (s, 3H, CH3), 2.00 (s, 3H, CH3); 13C-NMR
(75 MHz, CDCl3) δ 170.3, 170.0, 169.8, 169.6 71.6, 71.0, 69.6,
68.8, 42.2, 33.3, 21.15, 21.1, 21.0, 20.8; IR (KBr, cm−1): 2922,
2853, 1742, 1464, 1437, 1367, 1223, 1169, 1117, 1041, 721;
Anal. Calcd for C14H19BrO8: C, 42.55; H, 4.85; Found: C, 42.14;
H, 4.52.
rel-(1S,2S,3R,4R,5R)-5-Bromocyclohexane-1,2,3,4-tetrol (42)
Bromotetraacetate 38 (0.14 g, 0.35 mmol) was hydrolyzed with
HCl in MeOH as described above to give 42 (0.063 g, 78%).
The residue was crystallized from hexane–ethanol (1 : 1) to give
a colorless powder (0.056 g, 69%), mp, 191–193 °C. 1H-NMR
(300 MHz, CDCl3) δ 4.7 (br. S, 4H, OH), 4.2 (m, 1H), 3.9 (br. d,
J = 9.3 Hz, 1H), 3.75 (br. q, J = 8.5 Hz, 1H), 3.45 (br. T, J = 8.5
Hz, 1H), 2.12–1.95 (m, 2H); 13C-NMR (75 MHz, CDCl3) δ 74.8,
73.0, 70.4, 69.5, 47.8, 34.3; IR (KBr, cm−1): 3290, 1627, 1435,
1197, 1097, 1058, 1020, 997, 918, 873, 752, 665, 611; Anal.
Calcd for C6H11BrO4: C, 31.74; H, 4.88; Found: C, 32.02;
H, 4.53.
rel-(1S,2S,3R,4S,6S)-3,6-Dibromocyclohexane-1,2,4-triol (39)
Dibromotriacetate 35 (0.25 g, 0.6 mmol) was dissolved in
50 mL methanol and HCl gas was passed through the solution
for 20 min at room temperature. The neck of the flask was
closed and the solution was stirred at the same temperature
for 12 h. The solvent was removed under reduced pressure.
Bromoquercitol isomer 39 was obtained as a viscous and color-
less oil. Crystallization from ethanol gave colorless crystals
rel-(1S,2R,3R,4R,5R)-5-Methoxycyclohexane-1,2,3,4-tetraol (47)
Methoxytetraacetate 18 (0.4 g, 1.16 mmol) was hydrolyzed with
NH3(g) as described above to give 47 (0.18 g, 85%). It was crys-
tallized from ethanol to give a white solid (0.16 g, 76%), mp,
188–190 °C. 1H NMR (300 MHz, CD3OD) δ 4.88 (br. s, 2H, OH),
4.59 (s, 2H, OH), 3.96 (bt, J = 1.5 Hz, 1H, OCH), 3.75 (ddd,
J1,6eq = 4.7, J1,2 = 9.4, J1,6ax = 11.4 Hz, 1H, CH-OMe), 3.49–3.35
(m, 5H, 2 OCH and OCH3), 3.31–3.26 (m, 1H, OCH), 2.29 (dt,
J6eq,6ax = 12.3, J6eq,1 = J6eq,5 = 4.4 Hz, 1H, H6eq), 1.11 (bq,
J = 11.4 Hz, 1H, H6ax); 13C NMR (75 MHz, CD3OD) δ 77.9, 75.3,
74.3, 73.1, 67.86, 56.5, 34.0; IR (KBr, cm−1): 3331, 2938, 2835,
1417, 1354, 1107, 1058, 1043, 1009, 950, 920, 895, 831, 708,
691, 600, 565; Anal. Calcd for C7H14O5: C, 47.18; H, 7.92;
Found: C, 47.39; H, 8.00.
1
(0.14 g, 82%), mp, 202–204 °C. H-NMR (300 MHz, D2O) δ 4.7
(br. s, 3H, OH), 4.19–4.18 (m, 1H, H-3), 4.01 (q, J = 2.9 Hz, 1H,
H-4), 3.96–3.88 (m, 1H, H-6), 3.65 (t, J = 9.5 Hz, 1H, H-1),
3.62–5.59 (m, 1H, H-2), 2.49 (ddd, J = 15.2, 12.1, 2.6 Hz, 1H,
H-6ax), 2.17–2.12 (m, 1H, H-6eq); 13C-NMR (75 MHz, CDCl3)
δ 75.3, 70.6, 69.5, 56.6, 50.6, 36.5; IR (KBr, cm−1): 3474, 1410,
1387, 1317, 1252, 1169, 1113, 1040, 974, 937, 860, 796, 690,
655; Anal. Calcd for C6H10Br2O3: C, 24.85; H, 3.48; Found:
C, 24.44; H, 3.12.
rel-(1S,2S,3R,4S,5S)-5-Bromocyclohexane-1,2,3,4-tetraol (40)
rel-(1S,2S,3S,4R,5R)-5-Methoxycyclohexane-1,2,3,4-tetraol (48)
Bromotetraacetate 36 (0.3 g, 0.76 mmol) was hydrolyzed with
HCl in MeOH as described above to give bromoquercitol 40
(0.16 g, 89%) as colorless crystals from ethanol, mp,
158–161 °C. 1H-NMR (300 MHz, D2O) δ 3.94 (ddd, J = 13.1, 9.6,
4.4 Hz, 1H, H-5), 3.53 (quasi q, J = 2.3 Hz, 1H, H-1), 3.41–3.30
(m, 3H, H-2, H-3, and H-4), 2.27 (ddt, J = 14.2, 1.2, 3.8 Hz, 1H,
H-6eq), 1.91 (dddd, J = 14.2, 12.8, 2.5, 1.3 Hz, 1H, H-6ax);
13C-NMR (75 MHz, CDCl3) δ 77.7, 73.5, 73.3, 69.4, 50.2, 38.4;
IR (KBr, cm−1): 3539, 3318, 3217, 2922, 1634, 1481, 1416, 1375,
1344, 1296, 1262, 1244, 1177, 1098, 1071, 1028, 993, 945, 858,
787, 667; Anal. Calcd for C6H11BrO4: C, 31.74; H, 4.88; Found:
C, 31.43; H, 4.94.
Methoxytetraacetate 30 (0.32 g, 0.92 mmol) was hydrolyzed
with NH3(g) as described above to give 48 (0.15 g, 88%) as col-
orless crystals from ethanol, mp, 193–195 °C. 1H NMR
(300 MHz, CD3OD) δ 4.89 (bs, 4H, –OH), 3.89 (bs, 1H),
3.63–3.55 (m, 2H, OCH), 3.42 (s, 3H, OCH3), 3.34–3.29 (m, 1H,
OCH), 3.03 (ddd, J1,6eq = 4.7, J1,2 = 9.1, J1,6ax = 11.6 Hz, 1H, CH–
OMe), 2.29 (bdt, J6eq,6ax = 12.9, J6eq,1 = J6eq,5 = 4.7 Hz, 1H, H6eq),
1.11 (bq, J = 11.4 Hz, 1H, H6ax); 13C NMR (75 MHz, CD3OD)
δ 79.6, 73. 6, 73.2, 72.7, 67.2, 56.4, 31.1; IR (KBr, cm−1) 3408,
3310, 3140, 3140, 2926, 2827, 1368, 1273, 1198, 1144, 1053,
1011, 945, 881, 721, 665, 575; Anal. Calcd for C7H14O5:
C, 47.18; H, 7.92; Found: C, 46.98; H, 7.81.
rel-(1S,2S,3R,4S,5R)-4-Bromocyclohexane-1,2,3,5-tetraol (41)
Bromotetraacetate 37 (0.75 g, 1.90 mmol) was hydrolyzed with
rel-(1S,2S,3R,4S,5R)-5-Methoxycyclohexane-1,2,3,4-tetraol (49)
HCl in MeOH as described above to give 41 (0.39 g, 91%) as Methoxytetraacetate 31 (0.36 g, 1.04 mmol) was hydrolyzed
colorless crystals from n-hexane–ethanol, mp, 178–180 °C. with NH3(g) as described above to give 49 (0.17 g, 89%) as col-
1H-NMR (300 MHz, D2O) δ 4.6, (br. s, 4H, OH), 3.99 orless crystals from ethanol, mp, 92–93 °C (Lit. mp,
(dd, J = 9.7, 3.1 Hz, 1H), 3.96 (dd, J = 4.3, 2.9 Hz, 1H), 3.85 94–96 °C).23 1H-NMR (300 MHz, CD3OD) δ 4.89 (s, 4H, –OH),
(ddd, J = 11.5, 4.5, 3.1 Hz, 1H), 3.70–3.80 (m, 2H), 1.95 (ddt, 3.92–3.85 (m, 2H, OCH), 3.62–3.50 (m, 2H, OCH), 3.42 (s, 3H,
1H, J = 12.5, 1.3, 4.6 Hz, 1H, H-6eq), 1.57 (dt, J = 12.5, 11.6 Hz, H, OCH3), 2.16–2.04 (m, 1H, H-6), 1.72–1.66 (m, 1H, H-6′);
1H, H-6ax); 13C-NMR (75 MHz, D2O) δ 72.9, 71.9, 68.5, 65.9, 13C NMR (75 MHz, CD3OD) δ 79.2, 74.3, 72.7, 71.0, 69.1, 56.7,
58.6, 35.3; IR (KBr, cm−1): 3331, 3266, 3154, 2926, 2907, 2440, 28.8; IR (KBr, cm−1): 3331, 3307, 2925, 2832, 1452, 1391, 1323,
1522 | Org. Biomol. Chem., 2013, 11, 1511–1524
This journal is © The Royal Society of Chemistry 2013