反应详情

To a stirred suspension of LiAlH4 (0.352 g, 9.26 mmol) in THF at 10° C. was added a solution of (RS)-6-hydroxy-chroman-2-carboxylic acid (1.2 g, 6.18 mmol) in THF (25 ml) over 15 min. After allowing to warm to ambient temperature, 4N HCl (25 ml) and EtOAc (100 ml) was added and the mixture shaken. The aqueous phase was extracted with EtOAc (100 ml) and the combined organic extracts were washed with satd. NaCl (50 ml), dried with Na2SO4 and evaporated. The resulting solid was taken up in acetone (50 ml) then K2CO3 (0.94 g, 6.8 mmol) and benzyl bromide (0.81 ml, 6.8 mmol) were added and the mixture refluxed for 18 hr. The reaction mixture was filtered, evaporated to dryness and chromatographed over SiO2 (Merck 230-400 mesh) eluting with EtOAc-cyclohexane (3:7) to afford (RS)-6-benzyloxy-(chroman-2-yl)-methanol (1.0 g, 3.7 mmol, 60%) as a white solid Mp. 80-82° C., MS mn/e=270.1 (M+).

1. extractionThe aqueous phase was extracted with EtOAc (100 ml)
2. washthe combined organic extracts were washed with satd
3. dry with materialNaCl (50 ml), dried with Na2SO4
4. customevaporated
5. temperaturethe mixture refluxed for 18 hr
6. filtrationThe reaction mixture was filtered
7. customevaporated to dryness
8. customchromatographed over SiO2 (Merck 230-400 mesh)
9. washeluting with EtOAc-cyclohexane (3:7)