反应详情

温度

-78 °C

A 1M of solution of lithium diisopropylamide in a 3:5 mixture of hexanes/THF (8.25 ml) is added dropwise to (3R,7aS)-3-trichloromethyl-tetrahydro-pyrrolo[1,2-c]oxazol-1-one (1.51 g, prepared as described by Wang and Germanas Synlett 1999, 33-36.) in THF (5 ml) at −78° C. After stirring 30 minutes at −78° C. Eschenmoser's salt (2.78 g) is added. The reaction mixture is then allowed to warm to −40° C. with vigorous stirring over 1 hour and maintained for 2 hours at −40° C. Water is then added and the aqueous layer extracted with dichloromethane, the combined organic layers dried over sodium sulphate and evaporated. The residue is then purified by mormal phase chromatography eluting with a gradient from dichloromethane to 20% ethyl acetate in dichloromethane to give the title compound as a pale yellow oil.

1. temperatureto warm to −40° C.
2. stirringwith vigorous stirring over 1 hour
3. temperaturemaintained for 2 hours at −40° C
4. extractionthe aqueous layer extracted with dichloromethane
5. dry with materialthe combined organic layers dried over sodium sulphate
6. customevaporated
7. customThe residue is then purified by mormal phase chromatography
8. washeluting with a gradient from dichloromethane to 20% ethyl acetate in dichloromethane