4,6,6-Trichloro-7,7,7-trifluoro-3,3-dimethylheptanoic acid → Methyl 3-(2,2-dichloro-3,3,3-trifluoropropyl)-2,2-dimethyl-cyclopropane carboxylate

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Reaction Steps

The (−) enantiomer of the methyl ester of 4,6,6-trichloro-7,7,7-trifluoro-3,3-dimethylheptanoic acid (14.43 gm) was cyclised with sodium t-butoxide base (6.3 gm 100%) in t-butanol/DMF solvent at <0° C. to produce methyl 3-(2,2-dichloro-3,3,3-trifluoropropyl)-2,2-dimethyl-cyclopropane carboxylate which was isolated by quenching with water and extracting into dichloromethane. After washing with water and brine the product was obtained as a yellow/orange oil (10.1 gm) by topping off the dichloromethane solvent. The product obtained was analysed by GLC, GCMS and NMR to confirm the material was consistent with that of methyl 3-(2,2-dichloro-3,3,3-trifluoropropyl)-2,2-dimethyl-cyclopropane carboxylate and it had a 80/20 cis:trans ratio.

Provenance & Evidence