反应详情

Acetyl chloride (200 μL, 2.8 mmol) was added to a stirred solution of hemiacetals II (19.0 g, 46.7 mmol) in methanol (100 ml). The solution was stirred for 15 min at ambient temperature. Sodium bicarbonate (1.0 g) was added and the mixture was stirred for another 15 min. The mixture was filtered through a pad of Celite (5.5×1 cm) and washed with toluene. Evaporation of solvent of the filtrate gave crude acetals III (19.4 g, yield 98%) as a colorless syrup (HPLC purity >95%). This was used without further purification in the next step.

1. stirringthe mixture was stirred for another 15 min
2. filtrationThe mixture was filtered through a pad of Celite (5.5×1 cm)
3. washwashed with toluene
4. customEvaporation of solvent of the filtrate