反应详情

温度

25 °C

The diester 1 from Step (a) (23 g, MW 240, 0.096 mol) was dissolved in 300 ml DMF. Potassium t-butoxide (100 ml of a 1M solution in dry THF) was added through a syringe. The solution was stirred for 15 min at 25° C. [2-(trimethylsilyl)ethoxy]methyl chloride (SEM-chloride, 18.6 ml, 1.1 eq, MW 166, d 0.94) was added and a precipitate instantly formed. The reaction was stirred for 90 min at 25° C. The solvent was removed and the residue partitioned between ethyl acetate and water. The organic extract was dried over K2CO3 and concentrated. By TLC (SiO2, MeOH-CHCl3 /1-10) a single major spot was observed. This crude product (38 g, 106% yield) was used in subsequent steps without further purification.

1. additionwas added
2. customa precipitate instantly formed
3. customThe solvent was removed
4. customthe residue partitioned between ethyl acetate and water
5. extractionThe organic extract
6. dry with materialwas dried over K2CO3
7. concentrationconcentrated