反应详情

To a solution of 1,4-cyclohexanedione mono-2,2-dimethyltrimethylene ketal (3.76 g) and zinc chloride (about 1.0 mol/L, solution in diethyl ether, 1.90 mL) in tetrahydrofuran (63.0 mL), benzylmagnesium bromide (about 1.0 mol/L, solution in tetrahydrofuran, 24.7 mL) was added at 0° C. and thereafter the mixture was stirred at that temperature for 2.5 hours. To the reaction mixture, a saturated aqueous solution of ammonium chloride was added and three extractions were conducted with ethyl acetate. The combined organic layers were washed with saturated brine and thereafter dried over anhydrous magnesium sulfate. The desiccant was removed by filtration and the filtrate was concentrated under reduced pressure. The resulting residue was purified by silica gel column chromatography (n-hexane:ethyl acetate=95:5-60:40) to give 9-benzyl-3,3-dimethyl-1,5-dioxaspiro[5.5]undecan-9-ol as a colorless solid (1.28 g).

1. extractionthree extractions
2. washThe combined organic layers were washed with saturated brine
3. dry with materialdried over anhydrous magnesium sulfate
4. customThe desiccant was removed by filtration
5. concentrationthe filtrate was concentrated under reduced pressure
6. customThe resulting residue was purified by silica gel column chromatography (n-hexane:ethyl acetate=95:5-60:40)