Ammonia → (RS)-2-methyl-4-methylidene-3-(2,2,2-trifluoroethyl)cyclopent-2-en-1-yl (1R)-trans-3-(2-methyl-1-propenyl)-2,2-dimethylcyclopropanecarboxylate

Participants

Reaction Steps

Under ice-water cooling, 350 mg of (1R)-trans-3-(2-methyl-1-propenyl)-2,2-dimethylcyclopropanecarboxylic acid chloride was added dropwise to the mixed solution of 300 mg of (RS)-2-methyl-4-methylidene-3-(2,2,2-trifluoroethyl)cyclopent-2-en-1-ol, 5 mg of 2,6-di-tert-butyl-4-methylphenol, 185 mg of pyridine and 5 mg of 4-dimethylaminopyridine in 10 ml of dry terahydrofuran and then the resultant reaction mixture was allowed to react further 6 hours at room temperature. Then 10 ml of 10% aqueous ammonia solution was added to the solution and vigorously stirred for 2 hours. The reaction mixture was extracted three times with diethyl ether and the ether layers were combined. The combined layer was washed with brine and dried over anhydrous magnesium sulfate. After removal of the drying agent, the solvent was evaporated. The obtained residue was subjected to silica gel column chromatography to afford 280 mg of the desired (RS)-2-methyl-4-methylidene-3-(2,2,2-trifluoroethyl)cyclopent-2-en-1-yl (1R)-trans-3-(2-methyl-1-propenyl)-2,2-dimethylcyclopropanecarboxylate (Compound No.15). Yield 52% (Eluent: n-hexane/ethyl acetate=30/1, 2,6-di-tert-butyl-4-methylphenol 0.1% ) nD21 1.4805

Provenance & Evidence