Claims
- 1. A process for the preparation of cis 2,2-dimethylcyclopropane-1-carboxylic acid of the formula ##STR13## wherein X.sub.1 and X.sub.2 are both chlorine or bromine and when different are selected from the group consisting of fluorine, bromine and chlorine comprising reacting a compound of the formula ##STR14## wherein X.sub.1, X.sub.2 and X.sub.3 when identical are selected from the group consisting of chlorine and bromine and when at least two are different, are selected from the group consisting of fluorine, chlorine and bromine with a reducing agent to eliminate the X.sub.3 substituent which is the halogen with the higher atomic weight.
- 2. The process of claim 1 wherein the reducing agent is selected from the group consisting of zinc in acetic acid and magnesium.
- 3. A process for preparing a cis-3-(2,2-dihalovinyl)-2,2-dimethylcyclopropanecarboxylic acid of the formula ##STR15## wherein each X is the same or different and is a chlorine or bromine atom, and the carboxy and dihalovinyl groups are cis with respect to each other, which comprises treating a lactone of the formula ##STR16## wherein the X's are the same or different and have the values given above with a metal selected from zinc and magnesium in a solvent selected from acetic acid, alcohols and tetrahydrofuran thereby simultaneously opening the lactone ring and eliminating one X atom.
- 4. A process according to claim 3 wherein the lactone ring is opened and the X atom is eliminated with zinc in acetic acid.
- 5. A process according to claim 3 wherein X is a chlorine atom.
- 6. The process of claim 3 wherein the lactone is the lactone of 1R, cis 2,2-dimethyl-3-(1'hydroxy-2',2',2'-trichloroethyl)-cyclopropane-1-carboxylic acid to obtain 1R, cis2,2-dimethyl-3-(2',2'-dichlorovinyl)-cyclopropane-1-carboxylic acid.
Priority Claims (1)
Number |
Date |
Country |
Kind |
77 19612 |
Jun 1977 |
FRX |
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Parent Case Info
This is a division of Ser. No. 027,654 filed Apr. 6, 1979 now U.S. Pat. No. 4,281,182 which is a division of application Ser. No. 914,399 filed June 12, 1978, now U.S. Pat. No. 4,166,063.
US Referenced Citations (1)
Number |
Name |
Date |
Kind |
4254282 |
Kondo |
Mar 1981 |
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Non-Patent Literature Citations (1)
Entry |
March, "Advanced Organic Chemistry & Reactions, Mechanisms and Structure," pp. 771-772, (1968). |
Divisions (2)
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Number |
Date |
Country |
Parent |
027654 |
Apr 1979 |
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Parent |
914399 |
Jun 1978 |
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