Synthesis and extraction properties of oxathiacrown compounds containing benzyl groups

Bromination of Olefins with HBr and DMSO

“…After 12 h of stirring at 65 °C, the reaction was worked up and purified as described above to yield compound 4 as an oil (0.223 g, 80% yield): R f = 0.87 (hexanes/EtOAc 70:30 v/v); 1 H NMR (CDCl 3 , 500 MHz) δ 7.37–7.27 (m, 5H), 4.41–4.33 (m, 1H), 3.83 (dd, J = 10.5, 4.2 Hz, 1H), 3.64 (dd, J = 10.4, 8.9 Hz, 1H), 3.51 (dd, J = 14.5, 4.8 Hz, 1H), 3.14 (dd, J = 14.5, 7.8 Hz, 1H); 13 C NMR (CDCl 3 , 125 MHz) δ 136.9, 129.5, 128.5, 127.2, 52.4, 42.0, 36.0. 1 H and 13 C NMR spectral data are consistent with previously reported values …”

“…1 H and 13 C NMR spectral data are consistent with previously reported values. 25 trans-1,2-Dibromocyclohexane (8). The standard procedure was used with cyclohexene (101 μL, 1.0 mmol), HBr (48% aq, 0.56 mL, 5 mmol), and DMSO (1 mL).…”

“…The standard procedure was used with cyclopent-3-enecarboxylic acid (103 μL, 1.0 mmol), HBr (48% aq, 0.56 mL, 5 mmol), and DMSO (1 mL). After 12 h of stirring at 65 °C, the reaction was worked up and purified as described above to yield compound 24 as a white powder (167 mg, 61% yield): mp = 111−113 °C; R f = 0.51 (hexanes/EtOAc 70:30 v/v); 1 H NMR (CDCl 3 , 500 MHz) δ 4.63 (ddd, J = 4.8, 2.1, 1.2 Hz, 1H), 4.55 (dt, J = 6.2, 1.8 Hz, 1H), 3.45−3.33 (m, 1H), 3.11−2.97 (m, 2H), 2.68−2.57 (m, 1H), 2.49 (ddt, J = 15.0, 8.6, 1.5 Hz, 1H); 13 (1S,3R,4R)-3,4-Dibromocyclohexanecarboxylic Acid (25). The standard procedure was used with cyclohex-3-enecarboxylic acid (117 μL, 1.0 mmol), HBr (48% aq, 0.56 mL, 5 mmol), and DMSO (1 mL).…”