反应详情

To a 0° C. solution of the alcohol of Example 1, Step 3 (14.0 g, 57.8 mmol) in CH3CN (180 mL) were added pyridine (10.0 mL) and acetoxyacetyl chloride (12.7 g, 93.0 mmol) after a period of 7 h at r.t., DBU (15.0 mL) was added to the reaction mixture. After a period of 1 h at 80° C., a second portion of DBU (20.0 mL) was added. The reaction mixture was kept at 80° C. for 18 h. The reaction mixture allowed to cool to r.t. The mixture was diluted with EtOAc (500 mL) and H2O (500 mL) and acidified with 6NHCl. After the addition of brine (100 mL), the aqueous phase was extracted 2 times with EtOAc. The organic phase was evaporated to provide a brown residue. To the solid was added a 2:1 mixture of CH2Cl2 -toluene (150 mL). The solid was filtered and washed with CH2Cl2 -toluene to provide 7.0 g of the title compound.

1. waitThe reaction mixture was kept at 80° C. for 18 h
2. extractionthe aqueous phase was extracted 2 times with EtOAc
3. customThe organic phase was evaporated
4. customto provide a brown residue
5. additionTo the solid was added
6. filtrationThe solid was filtered
7. washwashed with CH2Cl2 -toluene