反应详情

To a solution of the acid of Step 1 (103 g, 0.356 mol), pyridine (58 mL, 0.717 mol) and 2-(trimethylsilyl)ethanol (61.2 mL, 0.427 mol) in CH3CN (270 mL) was added a solution of dicyclohexylcarbodiimide (73.4 g, 0.356 mol) in CH3CN (100 mL). The reaction mixture was stirred at r.t. for 2 h, at which point 5M oxalic acid in DMF solution (11 mL) was added. After stirring for 30 min, the suspension was filtered and the filtrate was diluted with EtOAc, washed with water and dried over MgSO4. The crude product was distilled under reduced pressure to give 109 g of the title compound as a colorless oil (bp 120°-140° C./0.4 mm Hg).

1. additionwas added
2. filtrationthe suspension was filtered
3. additionthe filtrate was diluted with EtOAc
4. washwashed with water
5. dry with materialdried over MgSO4
6. distillationThe crude product was distilled under reduced pressure