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:
Oct. 02, 2001
Filed:
Apr. 03, 2000
Cognis Deutschland GmbH, Duesseldorf, DE;
Abstract
The present invention relates to a method for preparing optically active 5-methtyl-2-(1-methtyl-butyl)-5-propyl-1,3-dioxan, wherein said method comprises the following steps: converting lactic acid methylic ester into the corresponding N,N-disubstituted amid (aminolysis with piperidine and/or pyrrolidine); protecting its free OH function by a reaction with ethylvinylether in the presence of p-pyridiniumtosylate as a catalyst; submitting the N-pentamethylen- or N-tetramethylenlactamide thus obtained to a Grignard reaction in a conventional way so as to produce the corresponding &agr;, &bgr;-unsaturated ketone; further separating in a conventional way (e.g. agitation with acetic acid) the protection group introduced during the second step; acetalating in a conventional way the ketone function (e.g. by reaction with 2-methyl-2-propyl-1,3-propanediol); mesylating the free OH function by reaction with methansulfonic acid chloride in pyridine; submitting the intermediate thus obtained to a reducing 1,2-transposition in the presence of trimethylammonium and diisobutylaluminum hydride while maintaining the sterochemistry; and converting by catalytic hydrogenation the dehydro compound thus abtained into optically active 5-methyl-2-(1-methyl-butyl)-5-propyl-1,3-dioxan. The optically active 5-methyl-2-(1-methyl-butyl)-5-propyl-1,3-dioxan of the present invention exhibits a remarkable scent profile as well as a high scent intensity and may be used as perfume.