反应详情

Benzyl 4-(acetyloxy)-3,3-dimethyl-1-oxo-2-oxa-8-azaspiro[4.5]decane-8-carboxylate (from step (i) above; 1.4 g) was dissolved in tetrahydrofuran and lithium borohydride (81 mg) was added. The mixture was heated under reflux for 2 h, cooled and quenched carefully with water and HCl (30 mL, 5N). The mixture was extracted with ethyl acetate and dried (MgSO4), and concentrated in vacuo. The crude product was purified by chromatography on silica using 2-5% methanol in dichloromethane as eluant to afford the product (340 mg).

1. temperatureThe mixture was heated
2. temperatureunder reflux for 2 h
3. temperaturecooled
4. customquenched carefully with water and HCl (30 mL, 5N)
5. extractionThe mixture was extracted with ethyl acetate
6. dry with materialdried (MgSO4)
7. concentrationconcentrated in vacuo
8. customThe crude product was purified by chromatography on silica using 2-5% methanol in dichloromethane as eluant