反应详情

To a dimethylsulfoxide (30 ml) solution of the 1,5,9-trioxaspiro[5.5]undec-3-ylmethanol (3.80 g, 20.2 mmol) obtained in the step (10a), sodium hydride, in oil (770 mg, 19.3 mmol as the content was regarded as 60%) was added at room temperature. The mixture was stirred at room temperature for 30 minutes in a nitrogen atmosphere. To the mixture, 4-chloro-2,3-dimethylpyridine 1-oxide (2.6 g, 16.5 mmol) was added, the mixture was stirred at 60° C. for 2.5 hours. After cooled to room temperature, the reaction mixture was concentrated. The residue was purified by silica gel column chromatography (NH silica gel: 200 g, elution solvent: heptane, heptane/ethyl acetate=1/1, 1/3, ethyl acetate, ethyl acetate/methanol=10/1) to obtain the title compound (3.38 g, yield: 66.2%) as a pale yellow gum.

1. additionwas added at room temperature
2. stirringthe mixture was stirred at 60° C. for 2.5 hours
3. temperatureAfter cooled to room temperature
4. concentrationthe reaction mixture was concentrated
5. customThe residue was purified by silica gel column chromatography (NH silica gel: 200 g, elution solvent: heptane, heptane/ethyl acetate=1/1, 1/3, ethyl acetate, ethyl acetate/methanol=10/1)