Reaction Steps
Compound 5.09 (4.0 g, 8.0 mmol) was dissolved in CH2Cl2 (80 mL) and pyridine (2.6 mL, 32 mmol) then chilled to 0° C. Phenyl chloroformate (1.1 mL, 8.8 mmol) was added and the reaction was stirred for 20 min then quenched with 20 mL MeOH and concentrated in vacuo. The residue was dissolved in CH2Cl2 then washed with H2O and brine. The organic layer was concentrated in vacuo and the residue was purified by silica gel chromatography (10% EtOAc/petroleum ether) to afford the title compound (5.0 g, 8.0 mmol, 100%). 1H NMR (500 MHz, CDCl3): δ ppm 7.36-7.25 (m, 7H, PhH), 7.22 (t, J=7.3 Hz, 1H, PhH), 7.10 (d, J=8.8 Hz, 2H, PhH), 4.97 (d, J=10.3 Hz, 1H, H-3), 4.95, 4.67 (ABq, J=11.2 Hz, OCH2Ph1H each,), 4.53 (d, J=7.8 Hz, 1H, H-1), 4.04-3.96 (m, 1H, OCHHCH2SiMe3), 3.89 (d, J=7.3 Hz, 2H, H-6), 3.64 (s, 1H, OH), 3.63-3.58 (m, 1H, OCHHCH2SiMe3), 3.54 (t, J=7.1 Hz, 1H, H-5), 3.38 (dd, J=10.3, 7.8 Hz, 1H, H-2), 1.36 (s, 3H, Me), 1.04 (t, J=8.8 Hz, 2H, OCH2CH2SiMe3), 0.91 (s, 9H, SiCMe3), 0.13, 0.12 (s, 3H each, SiMe2), 0.04 (s, 9H, SiMe3); 13C NMR (125 MHz, CDCl3): δ ppm 153.72, 151.34, 138.51, 129.43, 128.44, 127.66, 127.64, 125.97, 121.18, 103.63, 83.26, 79.14, 75.22, 74.80, 73.57, 68.06, 62.56, 25.94, 18.69, 18.26, 16.13, −1.29, −5.38, −5.55; HRMS calcd for C32H54NO8Si2 [M+NH4]+: 618.3044. found 618.9056.
