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:
Aug. 31, 1982
Filed:
Apr. 22, 1981
Kenji Saito, Toyonaka, JP;
Hiroshi Yamachika, Ibaraki, JP;
Sumitomo Chemical Company, Limited, Osaka, JP;
Abstract
A process for preparing cyclopentenolones in good yields which comprises treating a 4-hydroxy-4-R.sub.2 -5-R.sub.1 -2-cyclopentenone of the formula: ##STR1## wherein R.sub.1 is an alkyl group having not more than 6 carbon atoms, an alkenyl group having not more than 6 carbon atoms, an alkynyl group having not more than 6 carbon atoms or a group of the formula: ##STR2## (in which R.sub.3 is hydrogen, methyl or halogen) and R.sub.2 is a hydrogen atom or a methyl group, provided that when R.sub.2 is hydrogen, R.sub.1 is neither .alpha.-methylallyl nor .alpha.-methylpropargyl, in an aqueous medium in the presence or absence of a metal salt at a temperature of 20.degree. to 200.degree. C. to give the corresponding 2-R.sub.1 -3-R.sub.2 -4-hydroxy-2-cyclopentenone of the formula: ##STR3## wherein R.sub.1 and R.sub.2 are each as defined above.