Pyridine → Chloroprallethrin

Participants

Reaction Steps

3.4 Grams of pyridine was added to a mixture of 5.0 g of (S)-2-methyl-4-oxo-3-(2-propynyl)-cyclopent-2-enyl alcohol, 8.0 g of (1R)-trans-3-(2, 2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylic acid chloride and 50 ml of toluene under ice-cooling. The resulting mixture was allowed to react at room temperature for 12 hours. Thereafter, about 50 ml of a saturated aqueous ammonium chloride solution was added to the resultant reaction solution, which was then extracted with three 50-ml portions of diethyl ether. The combined diethyl ether layer was washed with a saturated aqueous sodium chloride solution, dried over anhydrous sodium sulfate and then concentrated under reduced pressure. The residue was subjected to a silica gel column chromatography followed by recrystallization from a mixed solvent of hexane and ethyl acetate to obtain 8.9 g (yield: 78%) of (S)-2-methyl-4-oxo-3-(2-propynyl)-cyclopent-2-enyl (1R)-trans-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylate (the present compound).

Provenance & Evidence