Degussa - Huls Ag

Degussa Aktiengesellschaft

Nongyuan Shi

Klaus Huthmacher

Steffen Krill

Horst Weigel

Bernd Drapal

Hans Joachim Hasselbach

Mario Scholz

Steffen Hasenzahl

Georg Markowz

Frank Hubner

Ralph McIntosh

Volker Hafner

Rainer Peter

Markus Julino

Frank H&uuml;bner

Christoph Weckenbecker

A process for the preparation of &bgr;,&ggr;,&dgr;-unsaturated ketones and/or &agr;,&bgr;,&ggr;,&dgr;-unsaturated ketones by the reaction of an unsaturated alcohol with an enol ether or mixture of enol ethers, with formation of ketals as a by-product, at temperatures of from 50&deg; C. to 200&deg; C., in the presence of an acid catalyst, whereby one or all of the reagents is/are heated to the reaction temperature of from 50&deg; C. to 200&deg; C. before the acid catalyst is added.

Process for the preparation of unsaturated ketones

Process for the preparation of unsaturated 4,5-allene ketones by reaction of tertiary propargyl alcohols with alkenyl alkyl ethers or ketals in the presence of aliphatic sulfonic acids or sulfonic acid salts.

Process for the preparation of unsaturated 4,5-allene ketones, 3,5-diene ketones and the corresponding saturated ketones

A process for the production of 2,3,5-trimethylhydroquinone diesters by aromatization of 2,6,6-trimethyl-2-cyclohexene-1,4-dione (4-oxoisophorone, ketoisophorone, KIP) with an acylating agent and an acidic soluble or insoluble catalyst, which process may be operated alternatively continuously or discontinuously. The process includes the following steps: a) a carboxylic anhydride having a C,to C,alkyl residue is used as the acylating agent, b) after the reaction, a proportion of the resultant carboxylic acid is optionally removed by distillation, c) the reaction solution is cooled, d) the product which has crystallized out is separated and washed, and e) the filtrate is returned to step a).

Process for the production of 2,3,5-trimethylhydroquinone diesters

Preparation of 2,3,5-trimethylhydroquinone diesters by rearrangement of 2,6,6-trimethylcyclohex-2-ene-1,4-dione (4-oxo-isophorone, ketoisophorone) in the presence of a solid, acid catalyst and an acylating agent, for example carboxylic acid anhydrides or carboxylic acid halides. The 2,3,5-trimethylhydroquinone diester may then optionally be saponified to the free 2,3,5-trimethylhydroquinone, which is a valuable building block in the synthesis of vitamin E.

Process for the preparation of 2,3,5-trimethylhydroquinone diesters

An improved process for the production of 2,3,5-trimethylhydroquinone by rearrangement of 4-oxoisophorone (ketoisophorone, 3,5,5-trimethyl-2-cyclohexen-1,4-dione) to yield a trimethylhydroquinone diester and the subsequent saponification thereof. Trimethylhydroquinone is in turn an important starting material for the production of vitamin E.

Process for the production of trimethylhydroquinone diesters and of

Growing community of inventors

Hanau, Germany

Nongyuan Shi