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:
Jul. 04, 1989
Filed:
Jul. 23, 1987
Wolfgang Spiegler, Worms, DE;
Norbert Goetz, Worms, DE;
Manfred Sauerwald, Roedersheim-Gronau, DE;
Toni Dockner, Meckenheim, DE;
Rolf Fischer, Heidelberg, DE;
Basf Aktiengesellschaft, Ludwigshafen, DE;
Abstract
3,4-dihydro-2H-pyrans I ##STR1## where R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are each H or C.sub.1 -C.sub.6 -alkyl and R.sup.3 is not C.sub.2 -C.sub.4 -alkyl when A is COOR.sup.5 and A is COOR.sup.5, .dbd.CHOR.sup.5, in which R.sup.5 is C.sub.1 -C.sub.4 -alkyl, or CH.sub.2 OR.sup.6, in which R.sup.6 is C.sub.1 -C.sub.4 -alkyl or is benzyl which is unsubstituted or substituted by C.sub.1 -C.sub.4 -alkyl, alkoxy or halogen, or is formyl, C.sub.2 -C.sub.4 -alkylcarbonyl or benzoyl which is unsubstituted or substituted by C.sub.1 -C.sub.4 -alkyl, alkoxy or halogen, are prepared by eliminating an alcohol from a 2-alkoxytetrahydropyran II ##STR2## where R.sup.7 is C.sub.1 -C.sub.18 -alkyl and A' is COOR.sup.5, CH(OR.sup.5).sub.2 or CH.sub.2 OR.sup.6, in which R.sup.5 and R.sup.6 have the meanings stated for I, the elimination being carried out by passing II, in the liquid or gaseous state, into a high boiling mineral oil at above the boiling point of the resulting dihydropyran I, removing I in gaseous form, replenishisng the high boiling mineral oil when it becomes enriched with byproducts, and removing the said mineral oil enriched with byproducts.