反应详情

温度

60 °C

To a solution of (3aR,4R,5R,6R,7aS)-4,5-dihydroxy-6-(hydroxymethyl)hexahydrobenzo[d]oxazol-2(3H)-one (2.99 g, 14.7 mmol) in DMF (10 mL) at room temperature was added p-toluenesulfonic acid monohydrate (210 mg, 1.10 mmol) followed by benzaldehyde dimethylacetal (6.72 g, 44.2 mmol). The mixture was heated at 60° C. under slightly diminished pressure for 3.5 h. After cooling, the reaction was diluted with water (100 mL) and extracted with EtOAc (2×60 mL). The extracts were washed with brine and dried with MgSO4. The solvent was evaporated to give the crude product. This was purified by silica gel column, eluted with 10-30% EtOAc in hexanes to provide (3aR,4R,4aR,8aR,9aS)-4-hydroxy-3-(methoxy(phenyl)methyl)-6-phenyloctahydro-2H-[1,3]dioxino[5′,4′:4,5]benzo[1,2-d]oxazol-2-one (3.33 g, 55%). MS m/z 434.6 (M+23, 100%); 1H NMR (400 MHz, CDCl3) δ 7.30-7.51 (m, 10H), 6.20 (s, 1H), 5.52 (s, 1H), 4.47-4.50 (m, 1H), 4.24 (dd, J=11.1 Hz, 4.7 Hz, 1H), 4.17 (d, J=2.5 Hz, 1H), 3.83-3.88 (m, 1H), 3.69 (s, 3H), 3.55 (t, J=11.0 Hz, 1H), 3.40 (t, J=10.1 Hz, 1H), 3.26 (t, J=6.8 Hz, 1H), 2.11-2.23 (m, 2H), 1.28-1.36 (m, 1H).

1. temperatureAfter cooling
2. extractionextracted with EtOAc (2×60 mL)
3. washThe extracts were washed with brine
4. dry with materialdried with MgSO4
5. customThe solvent was evaporated
6. customto give the crude product
7. customThis was purified by silica gel column
8. washeluted with 10-30% EtOAc in hexanes