反应详情

To a suspension of (3 aS,4R,5R,6R,7aS)-6-(((tert-butyldimethylsilyl)oxy)methyl)-2-oxooctahydrobenzo[d]oxazole-4,5-diyl dibenzoate (3.29 g, 6.27 mmol) in dry MeOH (50 mL) at room temperature was added a solution of HCl in 4:1 EtOAc-MeOH (1.5 M, 28 mL, 41.8 mmol). The mixture was stirred at room temperature for 2 h. The solvents were evaporated to give the crude product. This was purified by SiO2 column, eluted with 60-80% EtOAc in hexanes to give (3aS,4R,5R,6R,7aS)-6-(hydroxymethyl)-2-oxooctahydrobenzo[d]oxazole-4,5-diyl dibenzoate (1.87 g, 73%). MS m/z 434.1 (M+23, 100%); 1H NMR (400 MHz, CDCl3) δ 7.94 (d, J=7.8 Hz, 2H), 7.87 (d, J=7.8 Hz, 2H), 7.49 (t, J=7.8 Hz, 2H), 7.33 (t, J=7.8 Hz, 4H), 6.37 (s, 1H), 5.45 (dd, J=9.7 Hz, 6.8 Hz, 1H), 5.31 (t, J=10.0 Hz, 1H), 4.90-4.92 (m, 1H), 3.88 (t, J=6.8 Hz, 1H), 3.74 (dd, J=12.1 Hz, 2.5 Hz, 1H), 3.57 (dd, J=12.1 Hz, 2.0 Hz, 1H), 2.39 (d, J=13.8 Hz, 1H), 2.19-2.32 (m, 2H).

1. customThe solvents were evaporated
2. customto give the crude product
3. customThis was purified by SiO2 column
4. washeluted with 60-80% EtOAc in hexanes