反应详情

温度

-78 °C

To a solution of Intermediate 52 (4.26 g, 8.12 mmol) in THF (150 ml) at −78° C. was added LDA (1.5 M in THF, 16.24 ml, 24.36 mmol) slowly. The resulting mixture was stirred for 1.5 hrs at −78° C. before adding a solution of 1,2-dibromo-tetrachloroethane (3.97 g, 12.18 mmol) in THF (1 ml). Stirring was continued at −78° C. for 2 hrs, then the reaction mixture was quenched by addition of sat. aqueous NH4Cl solution and warmed up to r.t. The mixture was extracted with EtOAc and the organic layer was dried, filtered, and evaporated to dryness. Purification by flash chromatography (silica gel, cyclohexane/EtOAc gradient) yielded Intermediate 53.

1. stirringStirring
2. waitwas continued at −78° C. for 2 hrs
3. customthe reaction mixture was quenched by addition of sat. aqueous NH4Cl solution
4. temperaturewarmed up to r.t
5. extractionThe mixture was extracted with EtOAc
6. customthe organic layer was dried
7. filtrationfiltered
8. customevaporated to dryness
9. customPurification by flash chromatography (silica gel, cyclohexane/EtOAc gradient)