Reaction Steps
To a stirred solution of 5.08 (7.2 g, 11.6 mmol) in CH2Cl2 (137 mL) and H2O (8 mL) at 0° C. was added 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (3.4 g, 15.0 mmol). The reaction mixture was stirred for 1 h then diluted with CH2Cl2 and sequentially washed with saturated aqueous NaHCO3, H2O, and brine. After concentration of the organic phase in vacuo, the crude residue was purified by silica gel chromatography (25% EtOAc/petroleum ether) to afford the title compound (4.5 g, 9.0 mmol, 78%). 1H NMR (500 MHz, CDCl3): δ ppm 7.39-7.32 (m, 4H, PhH), 7.29 (t, J=6.8 Hz, 1H, PhH), 4.95, 4.68 (ABq, J=11.2 Hz, 1H each, OCH2Ph), 4.42 (d, J=7.8 Hz, 1H, H-1), 4.01-3.94 (m, 1H, OCHHCH2SiMe3), 3.90-3.80 (m, 2H, H-6), 3.60 (d, J=9.8 Hz, 1H, H-3), 3.60-3.54 (m, 1H, OCHHCH2SiMe3), 3.51 (br s, 1H, OH), 3.41 (t, J=6.8 Hz, 1H, H-5), 3.16 (dd, J=9.8, 7.8 Hz, 1H, H-3), 2.48 (br s, 1H, OH), 1.25 (s, 3H, Me), 1.05-0.99 (m, 2H, OCH2CH2SiMe3), 0.90 (s, 9H, SiCMe3), 0.11, 0.11 (s, 3H each, SiME2), 0.02 (s, 9H, SiMe3); 13C NMR (125 MHz, CDCl3): δ ppm 138.73, 128.56, 128.03, 127.86, 103.70, 80.62, 78.29, 75.77, 74.63, 73.80, 67.81, 62.57, 25.91, 18.68, 18.21, 15.31, −1.31, −5.39, −5.52; HRMS calcd for C25HSONO6Si2 [M+NH4]+: 516.3177. found 516.3165.
