Process for producing optically active 2-(2,2-dihalogenovinyl)-cyclopropane-1-carboxylic acids substituted in the 3-position, and derivatives thereof, as well as novel 4-(2,2,2-trihalogenoethyl)-cyclobutane-1-sulfonic acid salts
US4299967A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 17, 1979 |
| Grant date | Nov 10, 1981 |
| Priority date | — |
| Expiry date | Dec 17, 1999 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07C309/00
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
There is described a new process for the preparation of optically active 2-(2',2'-dihalogenovinyl)-cyclopropane-1-carboxylic acids substituted in the 3 position, and derivatives thereof. A racemate of certain cyclobutanones is reacted with a sulfurous acid salt of an optically active base to obtain a mixture of diastereomeric 4-2-(2',2',2'-trihalogenoethyl)-cyclobutane-1-sulfonic acid salts; this mixture is then separated into the pure diastereomeric sulfonic acid salts. Either the pure diastereomeric sulfonic acid salts are converted directly to the desired optically active products, or the optically active cyclobutanones obtained from the pure diastereomeric sulfonic acids salts by decomposition is converted, in the presence of a base to the desired product. Optionally, the product, optically active 2-(2',2'-dihalogenovinyl)-cyclopropane-1-carboxylic acids can be converted to their 1',2'-dibromo derivatives. SU PAC DETAILED DISCLOSURE The present invention relates to a novel process for the preparation of optically active 2-(2',2'-dihalogenovinyl)-cyclopropane-1-carboxylic acids substituted in the 3-position, and derivatives thereof, and also to novel 4-(2',2',2'-trihalogenoethyl…
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