Reaction Steps
A solution of 1-phenyl-7-(triisopropylsilyl)hept-5-en-3-ol (149 mg, 0.43 mmol, 1 eq) in acetonitrile (5 mL) was treated with Selectfluor (152 mg, 0.43 mmol, 1 eq) and stirred at room temperature under an atmosphere of argon for 18 h. The acetonitrile was removed under reduced pressure and the reaction was quenched with saturated aqueous sodium hydrogen carbonate (5 mL). It was then extracted with ether (3×10 mL), dried over MgSO4, filtered and the solvent removed under reduced pressure to give a pale yellow oil. Column chromatography (hexane:ether, 9:1) gave {[3-fluoro-5-(2-phenylethyl)tetrahydrofuran-2-yl]methyl}(triisopropyl)silane as a colourless oil (157 mg, 66% yield). For the major diastereomer depicted on the left hand side in the pair of formulae above: 1H NMR (400 MHz, CDCl3) δ 0.92-1.00 (dd, 1H, CH2Si, J=14.4, 5.6 Hz), 1.08-1.10 (m, 21H, SiCHCH3), 1.19-1.26 (m, 1H, CH2Si) 1.66-1.89 (m, 2H, PhCH2CH2), 1.93-2.02 (m, 1H, CH2CHF), 2.26-2.43 (m, 1H, CH2CHF), 2.60-2.83 (m, 2H, PhCH2), 3.70-3.81 (m, 1H, PhCH2CH2CHO), 4.06-4.17 (dddd, 1H, OCHCHF, J=27.6, 8.4, 5.6, 2.8 Hz), 4.83-4.98 (m, 1H, CHF); 13C NMR (100 MHz, CDCl3) δ 8.21-8.26 (CH2Si), 11.4 (Si(CH(CH3)2)3), 18.9 (Si(CH(CH3)2)3), 32.5 (PhCH2), 38.0 (PhCH2CH2), 39.2-39.4 (d, CH2CHF, J=21 Hz), 76.1 (PhCH2CH2CHO), 78.6-78.8 (d, CHFCHO, J=20 Hz), 94.6-96.5 (d, CHF, J=182), 125.7 (Ph), 125.8 (Ph), 128.3 (Ph), 128.4 (Ph), 142.1 (Ph); 19F NMR (376.5 MHz, CDCl3) δ −191.5 For the major diastereomer depicted on the right hand side in the pair of formulae above: 1H NMR (400 MHz, CDCl3) δ 0.92-1.00 (dd, 1H, CH2Si, J=14.4, 5.6 Hz), 1.08-1.10 (m, 21H, SiCHCH3 ), 1.19-1.26 (m, 1H, CH2Si) 1.66-1.89 (m, 2H, PhCH2CH2), 1.93-2.02 (m, 1H, CH2CHF), 2.26-2.43 (m, 1H, CH2CHF), 2.60-2.83 (m, 2H, PhCH2), 3.70-3.81 (m, 1H, PhCH2CH2CHO), 4.20-4.27 (m, 1H, OCHCHF), 4.78-4.93 (m, 1H, CHF); 13C NMR (100 MHz, CDCl3) δ 8.75-8.82 (CH2Si), 11.4 (Si(CH(CH3)2)3), 18.9 (Si(CH(CH3)2)3), 32.7 (PhCH2), 38.2 (PhCH2CH2), 39.6-39.9 (d, CH2CHF, J=21 Hz), 77.2 (PhCH2CH2CHO), 80.1-80.3 (d, CHFCHO, J=21 Hz), 94.0-94.5 (d, CHF, J=183), 125.8 (Ph), 128.3 (Ph), 128.4 (Ph), 128.5 (Ph), 142.1 (Ph); 19F NMR (376.5 MHz, CDCl3) δ −185.5; IR (v, cm−1) 3027 (Ar—H), 1496 (Ar), 1464 (Ar), 1384 (Ar), 1096 (C—O—C), 699 (Si—C); MS (GCT, CI+) m/z 226.2 [M+NH4]+ HRMS required for C22H41FNOSi: 382.2941, found 382.2935.
