反应详情

A solution of the product of stage (v) (712 mg) in dry tetrahydrofuran (7.5 ml) was added dropwise to a stirred suspension of lithium aluminium hydride (total of 363 mg) in dry tetrahydrofuran (15 ml) under nitrogen. The mixture was heated under reflux for 19 h, allowed to cool for 1 h and water (5 ml) was cautiously added dropwise. More water (10 ml) and aqueous sodium hydroxide (2N, 5 ml) were then added followed by chloroform (25 ml). The insoluble material was filtered off, washed thoroughly with chloroform and the filtrate layers separated. The aqueous layer was re-extracted with chloroform (2×25 ml) and the combined organic solution dried and evaporated to give crude title compound (750 mg) as an oil. This oil was purified by column chromatography on neutral activity I alumina (Type UGl, 22.5 g) eluting with ether-methanol (19:1) to give the title compound as an oil (287 mg). T.l.c. Alumina/ether-methanol (19:1) Rf 0.30.

1. temperatureThe mixture was heated
2. temperatureunder reflux for 19 h
3. temperatureto cool for 1 h
4. filtrationThe insoluble material was filtered off
5. washwashed thoroughly with chloroform
6. customthe filtrate layers separated
7. extractionThe aqueous layer was re-extracted with chloroform (2×25 ml)
8. customthe combined organic solution dried
9. customevaporated
10. customto give crude title compound (750 mg) as an oil
11. customThis oil was purified by column chromatography on neutral activity I alumina (Type UGl, 22.5 g)
12. washeluting with ether-methanol (19:1)