反应详情

To a solution of (2S,5S)-tert-butyl 2-((tert-butyldimethylsilyloxy)methyl)-5-hydroxy-4-(hydroxymethyl)-5,6-dihydropyridine-1(2H)-carboxylate (Intermediate 217, 13.7 g, 36.67 mmol) in dichloromethane (20 mL) at 0° C. was added pyridine (5.93 mL, 73.35 mmol) followed by dropwise addition of ethyl chloroformate (3.87 mL, 40.34 mmol). The reaction was allowed to warm to room temperature over 3 hours. Diluted with dichloromethane and washed with saturated NH4Cl. Extracted with dichloromethane three times, combined and dried over Na2SO4. Removed solvent to give title compound as a yellow oil (14.5 g, 89%).

1. washwashed with saturated NH4Cl
2. extractionExtracted with dichloromethane three times
3. dry with materialdried over Na2SO4