Hydrochloric Acid → Cyclopropanecarboxylic acid, 3-(2,2-dichloroethenyl)-2,2-dimethyl-, methyl ester

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Reaction Steps

0.4 Part of metallic sodium was dissolved in 30 parts of anhydrous methanol, and 2.7 parts of ethyl 3,3-dimethyl-4,6,6-trichloro-5-hexenoate prepared in the same manner as in Example 3 was added to the solution. The mixture was agitated for 2 hours under reflux of methanol. The liquid reaction mixture was cooled with ice water and neutralized with hydrogen chloride-saturated methanol. The precipitated solids were removed by filtration, and the filtrate was concentrated until the volume was reduced to 1/10. The concentrate was diluted with diethyl ether, washed with water and dried. Then, the solvent was removed by distillation, and the residue was subjected to distillation under reduced pressure to obtain 2.0 parts of methyl 2,2-dimethyl-3-(2',2'-dichlorovinyl)-cyclopropane-carboxylate having a boiling point of 68° - 70° C. under 0.2 mm Hg. The yield was 90 %. the cis : trans ratio of the product determined by gas chromatography was 22 : 78.

Provenance & Evidence