反应详情

To a stirred solution of the above di-ester (22) (1.35 g) in CH2Cl2 (20 mL) was added trifluoroacetic acid (80 mL). After stirring for 45 min the reaction was evaporated to dryness and re-evaporated twice with fresh toluene to remove any residual TFA. The oil which remained was then taken up in toluene (100 mL) and refluxed under Ar for 1 h. The product (23) was obtained after evaporation and purification by flash chromatography on silica gel eluted with 10% ethyl acetate in n-hexane (0.85 g, 85%).

1. customwas evaporated to dryness
2. customre-evaporated twice with fresh toluene
3. customto remove any residual TFA
4. temperaturerefluxed under Ar for 1 h