反应详情

A solution of 14.2 mL (185 mmol) of trifluoroacetic acid dissolved in 60 mL of dichloromethane was added dropwise under cooling with ice to a solution of 12.6 g (37.0 mmol) of tert-butyl 2-methyl-5-hydroxy-5-(trans-4-pentylcyclohexyl)pentanoate (36) obtained in the first step dissolved in 60 mL of dichloromethane, and reacted at room temperature for 5 hours. The reaction mixture was put in 200 mL of water, and then extracted with 100 mL of dichloromethane. The resulting organic layer was washed with water (150 mL×2) and dried over anhydrous sodium sulfate, and the solvent was distilled off under reduced pressure. The resulting residue was purified by column chromatography (developing solvent: heptane/ethyl acetate=9/1, column packing: silica gel) and then recrystallized from heptane to obtain 3.7 g (13.7 mmol) of 3-methyl-6-(trans-4-pentylcyclohexyl)tetrahydro-2-pyranone (Compound No. 6). The resulting compound was in the form of colorless crystals, and the yield based on the compound (36) was 37%.

1. additionwas added dropwise
2. customobtained in the first step
3. customreacted at room temperature for 5 hours
4. extractionextracted with 100 mL of dichloromethane
5. washThe resulting organic layer was washed with water (150 mL×2)
6. dry with materialdried over anhydrous sodium sulfate
7. distillationthe solvent was distilled off under reduced pressure
8. customThe resulting residue was purified by column chromatography (developing solvent: heptane/ethyl acetate=9/1, column packing: silica gel)
9. customrecrystallized from heptane