The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 02, 1976
Filed:
Aug. 23, 1974
Toshiko Honda, Osaka, JA;
Nobushige Itaya, Nishinomiya, JA;
Akio Higo, Nishinomiya, JA;
Fukashi Horiuchi, Kawanishi, JA;
Sumitomo Chemical Company, Limited, Osaka, JA;
Abstract
A novel process for preparing cis-chrysanthemic acid comprising (1) hydrolysis of trans-.delta.-halogenodihydrochrysanthemic acid or ester thereof under neutrally kept condition with an alkaline earth metal carbonate, (2) conversion of the obtained trans-.delta.-hydroxydihydrochrysanthemic acid ester into a mixture of cis-chrysanthemic acid and iso-cis-chrysanthemic acid by reacting with a strong base, and (3) separation of the cis-chrysanthemic acid from the mixture by selective conversion of the iso-cis-chrysanthemic acid with water in the presence of an acid catalyst into cis-dihydrochrysanthemolactone, followed by separation of the cis-chrysanthemic acid from the lactone with a caustic alkali and an acid. The present process is very useful for converting (-)-trans-chrysanthemic acid which is obtained, as a main remainder of racemic chrysanthemic acid prepared industrially, after (+)-trans-chrysanthemic acid was used for preparation of (+)-trans-chrysanthemic acid ester having a high insecticidal activity, into (+)-cis-chrysanthemic acid which is industrially valuable for preparation of insecticides.