反应详情

To a stirred and cooled (−78° C.) solution of the bromide 4 (205 mg, 0.65 mmol) in Et2O (4 mL) was added dropwise a 1.5 M solution of tert-butyllithium in pentane (0.92 mL, 1.37 mmol). After 40 min., dry gaseous CO2 was introduced into the reaction vessel. Progress of the reaction was followed by TLC analysis. After complete consumption of starting material 4 the reaction was quenched by the addition of saturated aqueous NaHCO3 solution. The mixture was allowed to warm to room temperature, and diluted with CH2Cl2. The aqueous layer was extracted with CH2Cl2 (2×), and the combined organic solutions were dried (MgSO4), filtered and concentrated. The residual yellow oil was dissolved in CH2Cl2:MeOH=20:1 and filtered through silicagel pad. The filtrate was concentrated and used directly in the next step.

1. customAfter complete consumption of starting material 4 the reaction
2. customwas quenched by the addition of saturated aqueous NaHCO3 solution
3. additiondiluted with CH2Cl2
4. extractionThe aqueous layer was extracted with CH2Cl2 (2×)
5. dry with materialthe combined organic solutions were dried (MgSO4)
6. filtrationfiltered
7. concentrationconcentrated
8. dissolutionThe residual yellow oil was dissolved in CH2Cl2
9. filtrationMeOH=20:1 and filtered through silicagel pad
10. concentrationThe filtrate was concentrated