Molecules 2011, 16
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1429 (-CH2); 1214 (C-O); 1076 (C-O); 896 (C-H). M.S. (m/z, %): 295 (25.7); 282 (18.4); 281 (64.2);
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267 (11.5); 222 (18.7); 221 (80.6); 207 (33.6); 147 (78.6); 73 (100). H-NMR: 7.08 (m, 2H, H-5 and
H-6); 7.01 (s, 1H, H-3); 4.10 (t, 2H, J = 6.5 Hz, H-3’); 2.68 (t, 2H, J = 7.8 Hz, H-1’); 2.26 (s, 6H,
CH3CO); 2.05 (s, 3H, CH3CO); 1.98 (m, 2H, H-2’). 13C-NMR: 171.1 (CH3CO); 168.4 (CH3CO); 168.3
(CH3CO); 141.9 (C-2); 140.2 (C-1); 140.1 (C-4); 126.5 (C-5); 123.2 (C-3); 123.1 (C-6); 63.6 (C-3’);
31.6 (C-2’); 29.9 (C-1’); 20.9 (CH3); 20.6 (2 × CH3). Compound 7; IR (cm−1): 2943 (C-H); 1707
(C=O); 1429 (-CH2); 1371 (-CH3); 1221 (C-O); 1017 (C-O); 905 (C-H). M.S. (m/z, %): 236 (5.3); 194
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(19.3); 153 (11.8); 152 (100); 124 (6.9); 123 (74.5); 109 (3.6); 77 (5.4). H-NMR: 7.06 (m, 2H, H-5
and H-6); 6.99 (d, 1H, J = 1.6 Hz, H-3); 2.57 (t, 2H, J = 7.7 Hz, H-1’); 2.28 (s, 6H, CH3CO); 1.63
(m, 2H, H-2’); 0.95 (t, 3H, J = 7.7 Hz, H-3’). 13C-NMR: 168.5 (CH3CO); 168.4 (CH3CO); 141.7 (C-2);
141.6 (C-1); 139.8 (C-4); 126.5 (C-5); 123.1 (C-6); 122.9 (C-3); 37.3 (C-2’); 24.2 (C-2’); 20.6
(2x CH3); 13.8 (CH3).
Synthesis of 4-(3-hydroxypropyl)-5-nitrobenzene-1,2-diol (8), 4-(2-hydroxypropyl)-5-nitrobenzene-1,2-
diol (9), 4-[3-(acetyloxy)propyl]-5-nitro-1,2-phenylene diacetate (10) and 3-(4,5-dihydroxy-2-
nitrophenyl)propyl acetate (11) from 2: The compound 2 (4-allyl-5-nitrobenzene-1,2-diol previously
synthesized [8,9]) (0.7 g, 0.4 mmol), was cooled at −5 °C, under an atmosphere of N2 and slowly
hydroborated with a 2.0 M solution of BH3·DMS/THF (0.20 mL) added dropwise at −10 °C for
15 min, and later the mixture was stirred at room temperature for 1 h. The resultant organoborane was
oxidized by a solution of sodium perborate (0.10 g, 0.70 mmol) and water (100 mL) and then the
mixture was stirred at room temperature for 2 h. Then, it was extracted with portions of ethyl ether
(4 × 50 mL) and the layers were separated. The organic layer was dried over MgSO4, filtered,
evaporated and re-dissolved in 5 mL of CH2Cl2. It was absorbed on silica, chromatographed by CC
eluting with mixtures of petroleum ether/EtOAc of increasing polarity (16.0:4.0→14.0:6.0). Isolated
two solids compounds. Solids were recrystallized in a mixture methanol/ether, purifying the product 8
(37.5 mg, 49.3%) and isomer 9 (4.6 mg, 6.1%). Compound 8, dark yellow, p.f.: 98.9–99.8 °C. IR
(cm−1): 3458 (O-H); 2921 (=C-H); 1593 (C=C); 1532 (NO2); 1457 (CH2); 1385 (CH3); 1331 (N=O);
880 (-C-H). 1H- NMR: 9.24 (s, 1H, OH); 8.88 (s, 1H, OH); 7.53 (s, 1H, H-6); 6.85 (s, 1H, H-3); 5.89
(b.s, 1H, OH); 4.39 (t, 2H, J = 6,4 Hz, H-3’); 2.88 (m, 2H, H-1’), 1.79 (m, 2H, H-2’). 13C-NMR: 151.3
(C-2); 144.2 (C-1); 141.5 (C-5); 132.2 (C-4); 118.5 (C-3); 112.9 (C-6); 61.8 (C-3’); 34.4 (C-2’); 30.1
(C-1’). Compound 9, dark yellow; p.f.: 104.3–105.8 °C. IR (cm−1): 3520 (O-H); 2923 (C-H); 1599
(C=C); 1530 (NO2); 1458 (-CH2); 1376 (-CH3); 1327 (N=O); 1043 (-C-O); 885(-C-H). 1H-NMR: 9.19
(s, 1H, OH); 8.84 (s, 1H, OH); 7.53 (s, 1H, H-6); 6.84 (s, 1H, H-3); 4.12 (m, 1H, H-2’); 3.73 (b.s., 1H,
OH); 3.36 (dd, 1H, J = 13.6, 3.9 Hz, H-1’a); 3.16 (dd, 1H, J = 13.6, 8.4 Hz, H-1’b); 1.33 (d, 3H, J = 6.6
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Hz, H-3’). C-NMR: 151.1 (C-2); 145.1 (C-1); 144.2 (C-5); 125.8 (C-4); 114.6 (C-3); 108.55 (C-6);
68.4 (C-2’); 39.1 (C-1’), 24.7 (C-3’). Then, this complex mixture (0.15 g) was dissolved in dry CH2Cl2
(50 mL), DMAP (1.08 mg) and Ac2O (0.40 mL, 4.23 mmol) were added and the mixture was stirred at
room temperature for 2 h. A cooled solution of 10% KHSO4 (approx. 50 mL) was then added to this
mixture. The watery layer was discarded and the organic layer was washed to neutrality with a
saturated solution of NaHCO3 and water. Then it was dried over MgSO4, filtered, evaporated and
re-dissolved in 5 mL of CH2Cl2. Subsequently, it was absorbed on silica and chromatographed by CC
with petroleum ether/EtOAc mixtures of increasing polarity (18.8:1.2→15.6:4.4). Two products were