[CH2:1]([C@:3]1([OH:17])[C:9]2[CH:10]=[CH:11][N:12]=[C:13]([O:14]C)[C:8]=2[CH2:7][O:6][C:5](=[O:16])[CH2:4]1)[CH3:2].[I-].[Na+].Cl[Si](C)(C)C.S([O-])([O-])=O.[Na+].[Na+].[Cl-].[Na+].O>O.C(#N)C>[CH2:1]([C@:3]1([OH:17])[C:9]2[CH:10]=[CH:11][NH:12][C:13](=[O:14])[C:8]=2[CH2:7][O:6][C:5](=[O:16])[CH2:4]1)[CH3:2]To a dry round-bottom flask was added lactone 10b (0.07 g, 0.3 mmol) followed by dry acetonitrile (1 mL). Sodium iodide (0.07 g, 0.49 mmol) was added followed by chlorotrimethylsilane (0.06 mL, 0.49 mmol). The resulting mixture was stirred at rt for 15 min at which point H2O was added (2.7 μL, 0.15 mmol) and the reaction mixture was heated to 60° C. for 7 h. The mixture was then poured into a 1:1 solution of 5% sodium sulfite/brine (7 mL) and then quickly extracted with ethyl acetate (4×5 mL). The organic layer was dried over MgSO4 and concentrated under reduced pressure. The crude product was subjected to flash chromatography (MeOH/CH2Cl2 5:95) to afford pure 11 as pale yellow oil (10.4 mg, 16%). IR (MeOH, NaCl,cm−1) 3370(br), 1655, 1049, 1025, 823, 768; 1H NMR (300 MHz, CD3OD) δ0.91 (t, J=7.5 Hz, 3H), 1.82 (m, 2H), 3.10 (d, J=13.8 Hz, 1H), 3.40 (d, J=13.8 Hz, 1H), 5.30 (d, J=15.2 Hz, 1H), 5.46 (d, J=15.2 Hz, 1H), 6.57 (d, J=7 Hz, 1H), 7.35 (d, J=7 Hz, 1H); 13C NMR (75 MHz, CDCl3/CD3OD) δ6.76, 35.22, 41.46, 60.98, 72.43, 105.93, 122.42, 132.76, 156.35, 161.60, 172.57; HRMS (EI) m/z calcd for C11H13NO4 (M+) 223.0845, found 223.0851; LRMS (EI) m/z 224(M+H, 32), 195(21), 163(43), 153(100), 91(40), 77(19), 55(24); [α]D23=+35.0 (c=0.08, MeOH).
불러오는 중…
