反应详情

Tert-butyl acetate (2.40 mL, 17.82 mmol) was added to a stirred and cooled (−78° C.) solution of lithium hexamethyldisilazide (17.8 mL, 1 M in tetrahydrofuran) in dry tetrahydrofuran (10 mL). After 30 minutes of stirring at −78° C., a solution of Example 93B (2.47 g, 8.9 mmol) in tetrahydrofuran was added dropwise into the solution. The resulting mixture was stirred for another hour before it was quenched with ammonium chloride and allowed to warm to room temperature. The mixture was partitioned with ether and water and the phases were separated. The organic phase was washed with brine, dried (magnesium sulfate), filtered and concentrated. The residue was purified by silica gel chromatography using 30% ethyl acetate in hexanes to provide the title compound as a yellow oil.

1. stirringAfter 30 minutes of stirring at −78° C.
2. stirringThe resulting mixture was stirred for another hour before it
3. customwas quenched with ammonium chloride
4. customThe mixture was partitioned with ether and water
5. customthe phases were separated
6. washThe organic phase was washed with brine
7. dry with materialdried (magnesium sulfate)
8. filtrationfiltered
9. concentrationconcentrated
10. customThe residue was purified by silica gel chromatography