反应详情

To a stirred solution of the compound prepared in Example 443 (2.04 g) in ethanol (50 mL) at ambient temperature was added a 21% solution of sodium ethoxide in denatured ethanol (4.24 mL). The reaction mixture immediately turned dark purple and was stirred at ambient temperature for 2.5 hours, then diluted with water (250 mL), and the resulting mixture was stirred at ambient temperature for 3 days. The mixture was poured into a separatory funnel and diluted with water (250 mL) and ethyl acetate (500 mL). The organic layer was dried over sodium sulfate and concentrated to give about 9 g of a dark semisolid. This material was partitioned between dichloromethane (200 mL) and water (100 mL). The organic layer was dried over sodium sulfate and concentrated. The residue was purified by chromatography on silica gel, eluting with 4/1 hexanes/ethyl acetate, to provide the title compound (0.87 g) with the following physical data.

1. stirringthe resulting mixture was stirred at ambient temperature for 3 days
2. additionThe mixture was poured into a separatory funnel
3. dry with materialThe organic layer was dried over sodium sulfate
4. concentrationconcentrated