反应详情

In 15.0 ml of methanol, is dissolved 1.45 g of trans-3-acetoxy-6-cyano-3,4-dihydro-2,2-dimethyl-4-(1,2-dihydro-2-oxo-4-t-butyldimethylsilyloxy-1-pyridinyl)-2H-benzo[b]pyran obtained in Example 4. Then, 3.00 ml of 4N hydrochloric acid in dioxane is added thereto at 0° C. and reacted at room temperature for 2 hours. The reaction mixture is concentrated under reduced pressure, the residue is mixed with water and ethyl acetate, and the product is extracted by ethyl acetate. The organic layer is washed with saturated aqueous solution of sodium chloride and dried over anhydrous sodium sulfate. Then, the inorganic matter is filtered off and the filtrate is concentrated under reduced pressure. The residue is purified by silica gel column chromatography using ethyl acetate as a developing solvent to obtain 1.06 g of trans-3-acetoxy-6-cyano-3,4-dihydro-2,2-dimethyl-4-(1,2-dihydro-2-oxo-4-hydroxymethyl-1-pyridinyl)-2H-benzo[b]pyran.

1. customat 0° C. and reacted at room temperature for 2 hours
2. concentrationThe reaction mixture is concentrated under reduced pressure
3. additionthe residue is mixed with water and ethyl acetate
4. extractionthe product is extracted by ethyl acetate
5. washThe organic layer is washed with saturated aqueous solution of sodium chloride
6. dry with materialdried over anhydrous sodium sulfate
7. filtrationThen, the inorganic matter is filtered off
8. concentrationthe filtrate is concentrated under reduced pressure
9. customThe residue is purified by silica gel column chromatography