反应详情

To a 0° C. solution of the alcohol of Example 1, Step 3 (29.5 g, 122 mmol) in CH3CN (350 mL) were added pyridine (25 mL) and acetoxyacetyl chloride (25 g, 183 mmol). After a period of 7 h at r.t., DBU (31 mL) was added to the reaction mixture. After a period of 1 h at 80° C., a second portion of DBU (35 mL) was added. The reaction mixture was kept at 80° C. for 18 h. The reaction mixture was allowed to cool to r.t. The mixture was poured onto ice-water (2.5 L) containing 100 mL of concentrated HCl. The brown solid was collected and dissolved in hot acetonitrile and was filtered through a plug of silica. The solvent was evaporated and the resultant solid was swished in EtOAc to give the title compound (21.2 g, 62%).

1. waitAfter a period of 1 h at 80° C.
2. waitThe reaction mixture was kept at 80° C. for 18 h
3. additionThe mixture was poured onto ice-water (2.5 L)
4. customThe brown solid was collected
5. dissolutiondissolved in hot acetonitrile
6. filtrationwas filtered through a plug of silica
7. customThe solvent was evaporated