反应详情

The product from Example 228c (1.36 g, 6.47 mmol) was dissolved in benzene (35 ml) and to this solution was added pyridinium-para-toluenesulfonate (0.20 g, 0.8 mmol). The mixture was heated to reflux for 23 h then concentrated under vacuum to give the title compound in quantitative yield sufficiently pure for use as isolated.

1. temperatureThe mixture was heated
2. temperatureto reflux for 23 h
3. concentrationthen concentrated under vacuum