1-Chloro-3-methyl-2-butene → HCID 53661470, compound

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Reaction Steps

Under an atmosphere of nitrogen, 486 mg (2.50 mmol) of (2,4-dihydroxyphenyl) (2-methylpropyl) ketone (52) and 784 mg (7.50 mmol, 3.00 equivalents) of 1-chloro-3-methyl-2-butene were dissolved in 7.0 ml of dry methanol. To the solution which was stirred at room temperature, a methanol (7.5 ml) solution of 405 mg (7.50 mmol, 3.00 equivalents) of sodium methoxide was slowly added dropwise. The resultant mixture was stirred at room temperature for three hours and then at 50° C. for one hour, and distilled at room temperature under a reduced pressure to remove methanol, and combined with ether. The ether layer was washed with a saturated aqueous ammonium chloride solution and saturated brine, dried over sodium sulfate, distilled off the solvent and obtain 661 mg of a red oily substance. The crude product was subjected to silica gel column chromatography (20 g of Wako Gel C-300, eluted with hexane:ether at varying ratios=50:1-4:1) to produce sequentially by fractionation in the order of elution 139 mg of {2-hydroxy-4-(3-methyl-2-butenyloxy)phenyl} (2-methylpropyl) ketone (53) in the form of a colorless oily substance and 41 mg of {2,4-dihydroxy-3-(3-methyl-2-butenyl)phenyl} (2-methylpropyl) ketone (54) in the form of colorless crystals.

Provenance & Evidence