[CH2:1]1[C:6](=O)N(I)[C:3](=[O:4])[CH2:2]1.CC1C=CC(S(O[I:20](O)[C:21]2[CH:26]=[CH:25][CH:24]=[CH:23][CH:22]=2)(=O)=O)=CC=1.[CH3:28][CH:29]1CCC[CH:30]1O.I[C:36]1C=CC=CC=1>CO>[I:20][C:21](=[C:26]1[CH2:25][CH2:24][CH2:23][CH:22]1[CH3:36])[C:3]([C:2]1[CH:1]=[CH:6][CH:30]=[CH:29][CH:28]=1)=[O:4]NIS (220 mg, 0.98 mmol) and HTIB (39 mg, 0.98 mmol) were added in one portion to a stirring solution containing 2-methyl-1-cyclopentanol in 10 mL of methanol. The reaction mixture was protected from light and stirred at room temperature for 16 hours. The reaction was worked up as usual. After evaporation of solvent under vacuum a light green oily residue was obtained (323 mg). The GC/Ms spectrum of the crude residue showed that starting material was present along with iodobenzene and the product. The product was isolated by means of silica gel column chromatography (40-140 mesh). Iodobenzene was eluted first with hexanes. The product was eluted next with 1:1 mixture of CH2Cl12 /hexanes and after solvent evaporation under vacuum, a light green oil was obtained (86.2 mg, 28%). The oil was characterized by spectroscopy: 1H-NMR (CDCl3): (E-isomer) δ1.24 (d, 7.2 Hz, 3H), 2.20-2.96 (m, 7H), 7.47 (t, 7.2 Hz, 2H), 7.58 (t, 7.2 Hz, 1H) , 7.92 (d, 7.8 Hz, 2H); (Z-isomer); δ0.92 (d, 7.2 Hz, 3H), 2.20-2.96 (m, 7H), 7.47 (t, 7.2 Hz, 2H), 7.58(t, 1H), 7.96 (d, 8 Hz, 2H); 13C-NMR (CDCl3) (Z-isomer) δ21.23, 24.07, 38.0, 40.69, 42.06, 87.39, 129.91, 130.1, 131.2, 131.32, 134.79, 135.76, 163.22, 194.02; (E-isomer) δ19.62, 26.87, 34.09, 34.72, 45.95, 85.55, 130.05, 131.19, 134.79, 135.59, 162.29, 1.94.20; IR (neat) 1665 (s), 1590 (w), 1450 (m), 1350 (w), 1300 (m), 1245(s), 1175 (m), 1050 (m), 1015 (m), 975 (w), 690 (m) cm-1 ; MS m/z (rel. int.) 326 (M+, 5), 311 (M-Ch3, 5), 199 (M-I, 11), 157 (49), 129(25), 105 (C6H5CO, 55), 77 (C6H5, 100).
Loading…
