Abstract: The invention pertains to a process for preparing a compound of formula (1) wherein R1 is independently chosen from C1-C6 alkyl, cycloalkyl, aralkyl and aryl, and R2, R3 and R4 are independently chosen from hydrogen and C1-C6 alkyl, cycloalkyl, aralkyl and aryl; which process comprises the steps of: a) contacting a compound of formula (2) wherein R1 and R2 are as above and M+ is a monovalent metal ion, with a compound of formula (3) wherein R3 and R4 are as above, to form a compound of formula (4) and b) followed by contacting the compound of formula (4) with an acid to give a compound of formula (1), wherein step (a) and/or step (b) are conducted in continuous mode.

Abstract: The invention pertains to a process for preparing a compound of formula (1) wherein R1 is independently chosen from C1-C6 alkyl, cycloalkyl, aralkyl and aryl, and R2, R3 and R4 are independently chosen from hydrogen and C1-C6 alkyl, cycloalkyl, aralkyl and aryl; which process comprises the steps of: a) contacting a compound of formula (2) wherein R1 and R2 are as above and M+ is a monovalent metal ion, with a compound of formula (3) wherein R3 and R4 are as above, to form a compound of formula (4) and b) followed by contacting the compound of formula (4) with an acid to give a compound of formula (1), wherein step (a) and/or step (b) are conducted in continuous mode.

Abstract: The invention relates to a method for carrying out reactions with participation of carbocations, whereby the initial most strongly exothermic phase of the reaction is carried out at high temperature (60 to 120° C.) and short residence time (1 to 30 seconds) in a microreactor and the subsequent less exothermic phases are carried out at optionally lower temperatures in two or more residence time units with longer residence times (1 to 30 seconds).

Abstract: The invention relates to a method for carrying out reactions with participation of carbocations, whereby the initial most strongly exothermic phase of the reaction is carried out at high temperature (60 to 120° C.) and short residence time (1 to 30 seconds) in a microreactor and the subsequent less exothermic phases are carried out at optionally lower temperatures in two or more residence time units with longer residence times (1 to 30 seconds).

Abstract: The invention relates to an improved method for producing chiral or enantiomer-enriched beta amino acids, -aldehydes, -ketones and gamma-amino alcohols, during which an allyl amine of formula (I), in which: R1 represents an alkyl radical, a cycloalkyl radical, an alkyl radical, a heterocycle radical or a condensed or bridged ring system; R2, R3, R4 and R5, independent of one another, can represent H or an alkyl radical, a cyclo alkyl radical, an aryl radical, a heterocycle radical or a condensed or bridged ring system or radicals R1, R2, R3 and R4, together, form ring systems that can optionally contain one or more heteroatoms, whereby radicals R1, R2, R3, R4 and R5 can be substituted once or a number of times, and; R6 represents H or an N-protective group, is transformed; a) by ozonolysis in a solvent and; b) subsequent decomposition of the peroxide-containing solution by means of an oxidizing agent or reductive reprocessing, into the corresponding amino compound of formula (II), in which R1, R2, R3, R4 and

Abstract: New genes containing a DNA sequence coding for hydroxynitrile lyase, which genes can be prepared via a primer combination based on the DNA sequence of the 5?-region of the mdl genes from the Prunus serotina and from Prunus amygdalus and/or a primer 2 based on the 3?-region of the DNA sequences of one of the hydroxynitrile lyase isoenzymes from Prunus serotina or from Prunus amygdalus, subsequent amplification with a DNA polymerase using a DNA from organisms, containing genes coding for hydroxynitrile lyase, as templates and cloning, and also recombinant proteins which can be prepared in suitable host cells by heterologous expression of the DNA sequence of said HNL genes, and proteins and fusion proteins derived therefrom and use of said proteins for preparing (R)- or (S)-cyanohydrins.

Abstract: New genes containing a DNA sequence coding for hydroxynitrile lyase, which genes can be prepared via a primer combination based on the DNA sequence of the 5?-region of the mdl genes from the Prunus serotina and from Prunus amygdalus and/or a primer 2 based on the 3?-region of the DNA sequences of one of the hydroxynitrile lyase isoenzymes from Prunus serotina or from Prunus amygdalus, subsequent amplification with a DNA polymerase using a DNA from organisms, containing genes coding for hydroxynitrile lyase, as templates and cloning, and also recombinant proteins which can be prepared in suitable host cells by heterologous expression of the DNA sequence of said HNL genes, and proteins and fusion proteins derived therefrom and use of said proteins for preparing (R)- or (S)-cyanohydrins.

Abstract: New genes containing a DNA sequence coding for hydroxynitrile lyase, which genes can be prepared via a primer combination based on the DNA sequence of the 5?-region of the mdl genes from Prunus serotina and from Prunus amygdalus and/or a primer 2 based on the 3?-region of the DNA sequences of one of the hydroxynitrile lyase isoenzymes from Prunus serotina or from Prunus amygdalus, subsequent amplification with a DNA polymerase using a DNA from organisms, containing genes coding for hydroxynitrile lyase, as templates and cloning, and also recombinant proteins which can be prepared in suitable host cells by heterologous expression of the DNA sequence of said HNL genes, and proteins and fusion proteins derived therefrom and use of said proteins for preparing (R)- or (S)-cyanohydrins.

Abstract: Process for generating 1O2 in which a ferrocene of the formula

Abstract: Process for the preparation of optically highly pure (R)- and (S)-&agr;-hydroxycarboxylic acids, in which either isolated, impure (R)- and (S)-&agr;-hydroxycarboxylic acids prepared by acidic hydrolysis of the (R)- and (S)- cyanohydrins obtained by enzyme-catalyzed addition of a cyanide group donor to the corresponding aldehydes or ketones are recrystallized in an aromatic hydrocarbon, optionally in the presence of a cosolvent, and optically highly pure (R)- and (S)-&agr;-hydroxycarboxylic acids having an optical purity of over 98%ee are obtained or the hydrolysis solution obtained by acidic hydrolysis of the (R)- and (S)-cyanohydrins is treated directly with an aromatic hydrocarbon, optionally in combination with a cosolvent, and is then extracted at hydrolysis temperature, whereupon after cooling of the organic phase the corresponding chemically and optically highly pure (R)- and (S)-&agr;-hydroxycarboxylic acids having an optical purity of over 98%ee crystallize out.

Abstract: Process for generating 1O2 in which an Sn(II) salt of the formula

Abstract: The invention relates to the production of (R)-enantiomeric, optically active cyanohydrins by reacting an aldehyde or a ketone with a cyanide group donor in the presence of (R) oxynitrilase, wherein a reaction mixture comprising a) an aldehyde or a ketone dissolved in an organic solvent; said organic solvent is immiscible or only slightly miscible with water, b) any aqueous R)-oxynitrilase solution and c) a cyanide group donor is stirred in such away that an emulsion is formed which remains intact until the end of the enzymatic reaction. After the enzymatic reaction has terminated, the (R)-cyanohydrin is isolated from the reaction mixture.

Abstract: New genes containing a DNA sequence coding for hydroxynitrile lyase, which genes can be prepared via a primer combination based on the DNA sequence of of the 5′-region of the mdl genes from Prunus serotina and from Prunus amygdalus and/or a primer 2 based on the 3′-region of the DNA sequences of one of the hydroxynitrile lyase isoenzymes from Prunus serotina or from Prunus amygdalus, subsequent amplification with a DNA polymerase using a DNA from organisms, containing genes coding for hydroxynitrile lyase, as templates and cloning, and also recombinant proteins which can be prepared in suitable host cells by heterologous expression of the DNA sequence of said HNL genes, and proteins and fusion proteins derived therefrom and use of said proteins for preparing (R)- or (S)-cyanohydrins.

Abstract: A process for the preparation of enantiomer-enriched aminofuranones and hydroxyfuranones in which an enantiomer-enriched cyanohydrin is acylated by an acylating agent, then cyclized at 40 to 90° C. in the presence of zinc or a zinc compound to the corresponding enantiomer-enriched aminofuranone, which is converted where appropriate by acid hydrolysis into the corresponding enantiomer-enriched hydroxyfuranone.

Abstract: Process for the stereoselective reduction of chiral &agr;- or &bgr;-keto esters which have a chiral center in the &ggr; position in an inert solvent at temperatures from −80 to +50° C. using a reductant obtained by reaction of NaBH4 and (D)- or (L)-tartaric acid, to give the corresponding diastereomeric hydroxy compounds in each case.

Abstract: Process for the preparation of optically highly pure (R)— and (S)—&agr;-hydroxycarboxylic acids, in which either isolated, impure (R)— and (S)—&agr;-hydroxycarboxylic acids prepared by acidic hydrolysis of the (R)— and (S)—cyanohydrins obtained by enzyme-catalyzed addition of a cyanide group donor to the corresponding aldehydes or ketones are recrystallized in an aromatic hydrocarbon, optionally in the presence of a cosolvent, and optically highly pure (R)— and (S)—&agr;-hydroxycarboxylic acids having an optical purity of over 98%ee are obtained or the hydrolysis solution obtained by acidic hydrolysis of the (R)— and (S)—cyanohydrins is treated directly with an aromatic hydrocarbon, optionally in combination with a cosolvent, and is then extracted at hydrolysis temperature, whereupon after cooling of the organic phase the corresponding chemically and optically highly pure (R)— and (S)—&agr;-hydroxycarboxylic acids having an optical purity

Abstract: Process for the preparation of the (S)-enantiomers of optically active cyanohydrins, in which a reaction mixture of a) an aldehyde or ketone dissolved in an organic, water-immiscible or slightly miscible diluent, b) an aqueous (S)-hydroxynitrile lyase solution and c) a cyanide group donor is stirred in such a way that an emulsion is formed which is maintained up to the end of the reaction by stirring.

Abstract: A process for stabilizing enantiomer-enriched cyanohydrins where citric acid and/or boric acid or boric anhydride is added as a stabilizer to the cyanohydrin to be stabilized.

Abstract: Process for the preparation of carboxylic acid succinimidyl esters by reaction of N-hydroxysuccinimide with a carboxylic acid and a halophosphoric acid ester of the formula ##STR1## in which R.sub.1 and R.sub.2 are identical or different and are a C.sub.2 - to C.sub.6 -alkyl radical or a phenyl radical, or R.sub.1 and R.sub.2 together form a C.sub.6 -aryl radical, in the presence of a base in a diluent at a temperature of 0.degree. C. up to 100.degree. C. and isolation of the corresponding carboxylic acid succinimidyl ester.

Abstract: A process for the preparation of carboxylic acid succinimidyl esters by reaction of N-hydroxysuccinimide with a carboxylic acid and a halophosphoric acid ester of the formula ##STR1## is desired, in which R.sub.1 and R.sub.2 are identical or different and are a C.sub.2 - to C.sub.6 -alkyl radical or a phenyl radical, or R.sub.1 and R.sub.2 The process is carried out in the presence of a base in a diluent at a temperature of 0.degree. C. up to 100.degree. C. with isolation of the corresponding carboxylic acid succinimidyl ester.