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:
May. 25, 1999
Filed:
Sep. 30, 1997
Tohru Nishioka, Wakayama, JP;
Shigeyoshi Tanaka, Wakayama, JP;
Junji Koshino, Wakayama, JP;
Osamu Yamashita, Wakayama, JP;
Tadahiro Ozawa, Ichikai-machi, JP;
Makoto Kohama, Wakayama, JP;
Kao Corporation, Tokyo, JP;
Abstract
To provide a simple process for economically preparing a dihydropyrane compound at a high productivity and a high reaction yield. To use a compound selected from the group consisting of a base and a compound (VIII) having a weaker coordination power to the Lewis acid than the aldehyde compound and having an activity to dissolve the Lewis acid, coordinated by the compound (VIII), in a solvent as a co-catalyst in reacting aldehyde with a diene compound in the presence of a Lewis acid to prepare a 5,6-dihydro-2H-pyrane compound represented by formula (III): ##STR1## in which R.sup.1 represents a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, aryl group which may be substituted with alkyl group, having 6 to 12 total carbon atoms; R.sup.2 and R.sup.3 represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.