反应详情

A mixture of 4-hydroxypiperidine (10 g, 0.10 mol), acetone (21.8 mL, 0.30 mol), acetic acid (5.7 mL, 0.10 mol) and tetrahydrofuran (150 mL) was stirred in an ice bath for 15 minutes. Sodium triacetoxyborohydride (31.3 g, 0.15mol) was then added portionwise and the mixture was stirred for a further 10 minutes. The reaction mixture was then warmed and stirred at room temperature for 10 minutes and at 40° C. for 2.5 hours. The solvent was evaporated under reduced pressure and the residue was dissolved in water (50 mL). The aqueous solution was basified to pH9 with 0.88 ammonia and the solution was stirred for 30 minutes. The reaction mixture was then extracted with diethyl ether (2×200 mL) and the combined extracts were dried over sodium sulfate and concentrated in vacuo to give a yellow oil. The oil was purified by column chromatography on silica gel, eluting with dichloromethane:methanol:0.88 ammonia, 96:4:1 to 90:10:1, to afford the title product as a yellow oil in quantitative yield, 14.6 g.

1. stirringthe mixture was stirred for a further 10 minutes
2. temperatureThe reaction mixture was then warmed
3. stirringstirred at room temperature for 10 minutes and at 40° C. for 2.5 hours
4. customThe solvent was evaporated under reduced pressure
5. dissolutionthe residue was dissolved in water (50 mL)
6. stirringthe solution was stirred for 30 minutes
7. extractionThe reaction mixture was then extracted with diethyl ether (2×200 mL)
8. dry with materialthe combined extracts were dried over sodium sulfate
9. concentrationconcentrated in vacuo
10. customto give a yellow oil
11. customThe oil was purified by column chromatography on silica gel
12. washeluting with dichloromethane