Reaction Steps
A mixture of (4R,6S)-4-(tert-butyldimethylsilyloxy)-6-(hydroxymethyl)-tetrahydropyran-2-one (8) (150 mg, 0.58 mmol) and Dess-Martin periodinane (380 mg, 0.86 mmol) in CH2Cl2 (15 mL) is stirred at ambient temperature for 3 hours. The mixture is diluted with t-BuMeO (20 mL), washed with saturated Na2S2O3 solution, saturated NaHCO3 solution, dried (MgSO4) and concentrated to give 130 mg (87%) of crude (2S,4R)-4-(tert-butyldimethylsilyloxy)-6-oxo-tetrahydro-2H-pyran-2-carbaldehyde (9) which is used in the next step without further purification. 1H NMR (300 MHz, CDCl3) δ: 9.82 (s, 1H), 5.09 (dd, J=11 Hz, J=4 Hz, 1H), 4.38 (m, 1H), 2.67 (d, J=4 Hz, 2H), 2.18−2.10 (m, 1H), 1.91−1.81 (m, 1H), 0.89 (s, 9H), 0.09, (s, 6H). 13C NMR (75 MHz, CDCl3) δ: 199.4, 168.0, 79.2, 62.9, 39.6, 31.4, 25.6, 17.9, −4.9. The hydrate form of (9) has following NMR spectra: 1H NMR (300 MHz, THF-d8) δ: 5.27 (d, J=6 Hz, 1H, OH), 5.19 (d, J=6 Hz, 1H, OH), 4.90−4.85 (m, 1H), 4.44−4.38 (m, 2H), 2.58 (dd, J=17 Hz, J=4 Hz, 1H), 2.44−2.36 (m, 1H), 1.92−1.87 (m, 2H), 0.91 (s, 9H), 0.10, (s, 6H). 13C NMR (75 MHz, THF-d8) δ: 168.7, 91.7, 79.0, 65.1, 40.3, 31.0, 26.2, 18.7, −4.8, −4.8.
