Degussa Aktiengesellschaft

Degussa - Huls Ag

Perstorp Specialty Chemicals Ab

Olaf Burkhardt

Thomas Haas

Rudolf Vanheertum

Marcus Morawietz

Agnes Bourrel

The reductive cleavage of linear and cyclic acetals, especially formals, in an aqueous medium containing a formate takes place by hydrogenation with hydrogen in the presence of a heterogeneous hydrogenation catalyst at a pH value of less than 7 at a temperature of over 200&deg; C. The catalyst-poisoning effect of the formate is overcome at over 200&deg; to 300&deg; C., especially from over 200&deg; to 280&deg; C., so that, in a suspension procedure, the weight ratio of metal having hydrogenating activity to acetal is less than 0.1.

Process for the reductive cleavage of linear and cyclic acetals especially formals

The acid-catalyzed intermolecular etherification of mono- or polyhydric alcohols and acid-catalyzed ether cleavage in the presence of water may be improved if etherification or ether cleavage is carried out in the presence of an acid catalyst and, additionally, a hydrogenation catalyst under a hydrogen atmosphere. The process relates in particular to the etherification of diols, triols and tetrols with the formation of hydroxyethers.

Process for intermolecular etherification and ether cleavage

The present invention relates to a process for the production of five-membered or six-membered cyclic ethers, in particular of anhydropolyols, by acid-catalysed cyclodehydration of polyols that contain at least two hydroxyl groups with a spacing enabling ring formation--that is to say, preferably with a spacing of 4 or 5 C atoms. The invention is directed in particular towards the production of anhydrotetritols, anhydropentitols and, particularly preferred, anhydrohexitols, from tetritols, pentitols and hexitols, respectively.

Growing community of inventors

Alzenau, Germany

Olaf Burkhardt