Abstract: Described are alkoxylated glycerol acetals according to Formulas (Ia) and (Ib) wherein R1 represents a linear or branched, saturated or unsaturated and optionally substituted hydrocarbyl residue comprising 6 to 22 carbon atoms and 0 or 1 to 3 double bonds, a benzyl or furfuryl radical, R2 is selected from hydrogen, an alkyl, alkenyl or hydroxyalkyl group having 6 to 22 carbon atoms or an acyl group having 6 to 22 carbon atoms and 0 or 1 to 3 double bonds, AO represents an ethylene oxide, a propylene oxide, a butylene oxide unit, or their mixtures, and n is an integer of about 1 to about 100.

Abstract: The invention relates to a catalyst for catalysing the polymerisation of epoxides, and which is to be improved such that it allows a more efficient reaction to be carried out. This is achieved by providing a catalyst obtainable by mixing a) at least one double metal cyanide compound, b) at least one organic complexing agent, and c) at least one primary alcohol with 6 to 24 C atoms. In addition, the invention relates to a method for the polymerisation of epoxides, and to the use of the claimed catalyst for the polymerisation of epoxides and the copolymerisation of epoxides with carbon dioxide.

Abstract: Described are alkoxylated glycerol acetals according to Formulas (Ia) and (Ib) wherein R1 represents a linear or branched, saturated or unsaturated and optionally substituted hydrocarbyl residue comprising 6 to 22 carbon atoms and 0 or 1 to 3 double bonds, a benzyl or furfuryl radical, R2 is selected from hydrogen, an alkyl, alkenyl or hydroxyalkyl group having 6 to 22 carbon atoms or an acyl group having 6 to 22 carbon atoms and 0 or 1 to 3 double bonds, AO represents an ethylene oxide, a propylene oxide, a butylene oxide unit, or their mixtures, and n is an integer of about 1 to about 100.

Abstract: The invention relates to the implementation of enzyme-catalysed reactions in the presence of ionic liquids.

Abstract: The invention relates to the implementation of enzyme-catalysed reactions in the presence of ionic liquids.

Abstract: The invention relates to the implementation of enzyme-catalysed reactions in the presence of ionic liquids.

Abstract: The invention relates to the implementation of enzyme-catalysed reactions in the presence of ionic liquids.

Abstract: Furanosides or pyranosides can be reacted with pyruvate and converted into sialic acids in good yields by an enzymatic synthesis, using a suitable aldolase, where the concentration of aldolase, per 50 mM of pyruvate, is 1 to 2,500 U*/ml. For example, 3-fluoroneuraminic acid and other 3,3-didesoxy-3-fluorononulopyranosonic acid derivatives can be prepared in this manner. The F-atom in the resulting sialic acid (which can be 19F or 19F and 18F) provides a label which makes possible studies of mammalian physiology and diagnosis of mammalian diseases.

Abstract: The invention involves a procedure for the catalytic enantioselective reduction of ketones to chiral alcohols. Heretofore, this reaction was carried out batch-wise. Because, in this procedure, one utilizes a catalyst increased in size with polymer, it is possible to carry out the reaction in a quasi-continuous manner in a membrane reactor. In contrast to the state of the art, one thus dramatically increases the operative life of the catalyst.

Abstract: In a process for the continuous enzyme-catalyticzed enzymatic production of hydrophobic products in an aqueous solution of a reaction mixture, the product is extracted from the product containing reaction mixture by way of a product-permeable microporous membrane into an organic solvent and the product-depleted reaction mixture is recycled.

Abstract: The invention relates to a process for the production of cytidine 5'-monophosphosialic acids which comprises reacting a sialic acid with cytidine 5'-triphosphate in the presence of a cell extract of a naturally occurring microorganism having cytidine 5'-monophospho-N-acetylneuraminic acid synthetase activity, the extract optionally having been subjected to one purification step.

Abstract: The preparation of optically-active cyanohydrins from the corresponding oxo compounds is disclosed. The reaction of the oxo compounds with hydrocyanic acid is carried out in an organic solvent in the presence of (R)- or (S)-oxynitrilase (4.1.2.10) and (4.1.2.11), respectively, being solubilized in a lyotropic liquid crystal. Compounds which upon hydrolysis produce increased pH values are excluded as surface active agents. Preferably, surface active agents, the organic solvent and an aqueous buffer solution with a pH of 3 to 6, are mixed together to obtain a liquid crystal/organic solvent two-phase system. The liquid crystal is preferably fixed on a porous support, in particular a glass support. The reaction is carried out in a flow-through reactor which contains the liquid crystal in the abovementioned form or in thin layers adjacent to narrow flow channels, the borders of which are liquid permeable and through which the substrate-containing solvent is passed.

Abstract: A process for obtaining N-acetylneuraminic acid from N-acetylglucosamine is disclosed. The process is carried out in a reactor which contains both N-acylglucosamine-2-epimerase (E.C. 5.1.3.8) which isomerizes GlcNAc into ManNAc, and N-acetylneuraminic acid pyruvate lyase (E.C. 4.1.3.3) which catalyzes the reaction of the resulting ManNAc with pyruvic acid to give Neu5Ac. GlcNAc and Pyr are fed into the reactor and Neu5Ac is obtained in the outflow. The process is preferably carried out continuously and in particular in an enzyme membrane reactor at pH 7.5 and 25.degree. C., especially using residence times of 0.2 to 10 h, and with an excess of GlcNAc in comparison with Pyr which is subsequently added if necessary. Epimerase and lyase are preferably present in the reactor in a ratio of activities which is equivalent to the reciprocal value of the quotient of the conversion rates.

Abstract: An enzymatic reaction of aliphatic, aromatic or heteroaromatic aldehydes or ketones with hydrocyanic acid to form the corresponding (R)-cyanohydrins or (S)-cyanohydrins is carried out in an aqueous medium in the presence of (R)-oxynitrilase (4.1.2.10) or oxynitrilase (4.1.2.11) under acid conditions and at temperatures such that the competing chemical reaction and racemization are negligible compared with the enzymatic synthesis. The process is preferably carried out at a pH of .ltoreq.4.5 and at reaction temperatures between -5.degree. C. and +50.degree. C. The reaction is preferably carried out continuously, advantageously in an enzyme membrane reactor. Of particular interest is the conversion of aromatic aldehydes into the corresponding optically active cyanohydrins.