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:
Jun. 16, 1987
Filed:
Sep. 20, 1985
Hans-Georg Schmidt, Niederkassel, DE;
Dynamit Nobel AG, Troisdorf Bez Koeln, DE;
Abstract
Disclosed is a process for preparing cis-trans isomer mixtures of 2,2-dimethyl-3(.beta.,.beta.-dichlorovinyl)-cyclopropane-1-carboxylic acid esters, having a high cis/trans isomer ratio, wherein a 4,4-dimethyl-5-halogen-6-alkoxytetrahydro-pyrone or a 3,3-dimethyl-4-halogen-5-oxo-pentanic acid ester is reacted with dichlorophosphonic acid esters in the presence of alkali alcoholates or alkali hydrides or lithium alkyls. Also disclosed are novel starting tetrahydropyrone compounds usable in the above process, and a process for preparation of the novel compounds which includes reacting .beta.,.beta.-dimethyl-.gamma.,.delta.-dihalogen-.delta.-valerolactones with alkali alcoholates at reaction temperatures between -10.degree. and +50.degree. C.