(2S,3S,4S)-2-甲基-3,4-二(苯甲氧基)-3,4-二氢-2H-吡喃

反应条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: A mixture of (2S,3S,4S)-3,4-bis(benzyloxy)-2-methyl-3,4-dihydro-2H-pyran (0.621 g, 2.00 mmol) and NaHCO3 (17.0 mg, 0.200 mmol) in MeOH (0.22 ml) and DCM (7 mL) was treated with ozone at −78° C. until the solution became light blue in color. The mixture was purged with nitrogen until colorless, diluted with MeOH (7 mL), and treated with a solution of NaBH4 (0.454 g, 12.0 mmol) and NaOAc (0.335 g, 4.08 mmol) in H2O (7 mL). The mixture was slowly warmed to room temperature and stirred for 12 h. The mixture was diluted with EtOAc and washed with H2O. The organic layer was separated and the aqueous layer was extracted with EtOAc. The combined organic phases were washed with brine, dried over MgSO4, filtered, and the filtrate concentrated. The crude residue was purified by flash chromatography (SiO2, hexanes/EtOAc gradient) to yield the title compound as a colorless oil (0.590 g, 93%): IR (neat) 3389, 2876, 1453, 1064, 733, 696 cm−1; 1H NMR (400 MHz, CDCl3) δ 7.39-7.27 (m, 10H), 4.64 (s, 2H), 4.63 (s, 2H), 4.06-3.97 (m, 1H), 3.92-3.83 (m, 1H), 3.80-3.73 (m, 2H), 3.47 (dd, J=6.2, 4.3 Hz, 1H), 2.92 (d, J=4.9 Hz, 1H), 2.23 (dd, J=6.9, 4.9 Hz, 1H), 1.24 (d, J=6.4 Hz, 3H); 13C NMR (101 MHz, CDCl3) δ 137.91, 137.71, 128.69, 128.62, 128.23, 128.19, 128.09, 81.72, 79.53, 73.63, 72.78, 67.66, 61.45, 19.74; ESIMS m/z 339.2 ([M+Na]+). The mixture was purged with nitrogen until colorless, diluted with MeOH (7 mL) washed with H2O The organic layer was separated the aqueous layer was extracted with EtOAc The combined organic phases were washed with brine dried over MgSO4 filtered the filtrate concentrated The crude residue was purified by flash chromatography (SiO2, hexanes/EtOAc gradient)

反应条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: A mixture of (2S,3S,4S)-3,4-bis(benzyloxy)-2-methyl-3,4-dihydro-2H-pyran (0.621 g, 2.00 mmol) and NaHCO3 (17.0 mg, 0.200 mmol) in MeOH (0.22 ml) and DCM (7 mL) was treated with ozone at −78° C. until the solution became light blue in color. The mixture was purged with nitrogen until colorless, diluted with MeOH (7 mL), and treated with a solution of NaBH4 (0.454 g, 12.0 mmol) and NaOAc (0.335 g, 4.08 mmol) in H2O (7 mL). The mixture was slowly warmed to room temperature and stirred for 12 h. The mixture was diluted with EtOAc and washed with H2O. The organic layer was separated and the aqueous layer was extracted with EtOAc. The combined organic phases were washed with brine, dried over MgSO4, filtered, and the filtrate concentrated. The crude residue was purified by flash chromatography (SiO2, hexanes/EtOAc gradient) to yield the title compound as a colorless oil (0.590 g, 93%): IR (neat) 3389, 2876, 1453, 1064, 733, 696 cm−1; 1H NMR (400 MHz, CDCl3) δ 7.39-7.27 (m, 10H), 4.64 (s, 2H), 4.63 (s, 2H), 4.06-3.97 (m, 1H), 3.92-3.83 (m, 1H), 3.80-3.73 (m, 2H), 3.47 (dd, J=6.2, 4.3 Hz, 1H), 2.92 (d, J=4.9 Hz, 1H), 2.23 (dd, J=6.9, 4.9 Hz, 1H), 1.24 (d, J=6.4 Hz, 3H); 13C NMR (101 MHz, CDCl3) δ 137.91, 137.71, 128.69, 128.62, 128.23, 128.19, 128.09, 81.72, 79.53, 73.63, 72.78, 67.66, 61.45, 19.74; ESIMS m/z 339.2 ([M+Na]+). The mixture was purged with nitrogen until colorless, diluted with MeOH (7 mL) washed with H2O The organic layer was separated the aqueous layer was extracted with EtOAc The combined organic phases were washed with brine dried over MgSO4 filtered the filtrate concentrated The crude residue was purified by flash chromatography (SiO2, hexanes/EtOAc gradient)

反应条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: A mixture of (2S,3S,4S)-3,4-bis(benzyloxy)-2-methyl-3,4-dihydro-2H-pyran (0.621 g, 2.00 mmol) and NaHCO3 (17.0 mg, 0.200 mmol) in MeOH (0.22 ml) and DCM (7 mL) was treated with ozone at −78° C. until the solution became light blue in color. The mixture was purged with nitrogen until colorless, diluted with MeOH (7 mL), and treated with a solution of NaBH4 (0.454 g, 12.0 mmol) and NaOAc (0.335 g, 4.08 mmol) in H2O (7 mL). The mixture was slowly warmed to room temperature and stirred for 12 h. The mixture was diluted with EtOAc and washed with H2O. The organic layer was separated and the aqueous layer was extracted with EtOAc. The combined organic phases were washed with brine, dried over MgSO4, filtered, and the filtrate concentrated. The crude residue was purified by flash chromatography (SiO2, hexanes/EtOAc gradient) to yield the title compound as a colorless oil (0.590 g, 93%): IR (neat) 3389, 2876, 1453, 1064, 733, 696 cm−1; 1H NMR (400 MHz, CDCl3) δ 7.39-7.27 (m, 10H), 4.64 (s, 2H), 4.63 (s, 2H), 4.06-3.97 (m, 1H), 3.92-3.83 (m, 1H), 3.80-3.73 (m, 2H), 3.47 (dd, J=6.2, 4.3 Hz, 1H), 2.92 (d, J=4.9 Hz, 1H), 2.23 (dd, J=6.9, 4.9 Hz, 1H), 1.24 (d, J=6.4 Hz, 3H); 13C NMR (101 MHz, CDCl3) δ 137.91, 137.71, 128.69, 128.62, 128.23, 128.19, 128.09, 81.72, 79.53, 73.63, 72.78, 67.66, 61.45, 19.74; ESIMS m/z 339.2 ([M+Na]+). The mixture was purged with nitrogen until colorless, diluted with MeOH (7 mL) washed with H2O The organic layer was separated the aqueous layer was extracted with EtOAc The combined organic phases were washed with brine dried over MgSO4 filtered the filtrate concentrated The crude residue was purified by flash chromatography (SiO2, hexanes/EtOAc gradient)