Degussa Aktiengesellschaft

Studiengesellschaft Kohle Mbh

Marc Samson

Axel Kleemann

Helmut Bonnemann

Karlheinz Drauz

Jurgen Martens

Rudolf Fahnenstich

Kleemann, Axel

The invention is directed to a cyclic acetal of N-acylglutamic acid-.gamma.-semialdehyde of the formula ##STR1## in which A is an unsubstituted alkylene group having 2 to 3 carbon atoms or such an alkylene group substituted by 1 to 2 methyl groups and R is a methyl, methoxy, phenyl, or benzyloxy group and to a method of producing a compound of formula (I) by reaction of a compound of the general formula ##STR2## in which A is as defined above, with hydrogen cyanide or a cyanide ion supplying compound, ammonia or an ammonium ion supplying compound and carbon dioxide or a carbonate ion supplying compound and basic hydrolysis of the reaction mixture obtained and reaction of the hydrolysis mixture with a suitable acylating compound and use of the compounds of formula (I) to produce .alpha.-N-acyltryptophane.

Cyclic acetals of N-acylglutamic acid-.gamma.-semialdehydes, process for

The invention is directed to 4-methylmercapto-2-cacetoxy-butyraldehyde of the formula ##STR1## and a process for its production by hydroformylating 3-methylmercapto-1-acetoxy-propene-1 of the formula ##STR2## 4-methylmercapto-2-acetoxy-butyraldehyde can be used as an intermediate product for the production of 4-methylmercapto-2-hydroxy-butyric acid, the hydroxy analogue of methionine.

4-Methylmercapto-2-acetoxy-butyraldehyde

The invention is directed to cyclic acetals of glutamic acid-.gamma.-semialdehyde of the formula ##STR1## in which A is an unsubstituted alkylene group having 2 to 3 carbon atoms or such an alkylene group substituted by 1 to 2 methyl groups and to a method of producing a compound of formula (I) by reaction of a compound of the general formula ##STR2## in which A is as defined above with hydrogen cyanide or a cyanide ion supplying compound, ammonia or an ammonium ion supplying compound and carbon dioxide or a carbonate ion supplying compound and basic hydrolysis of the reaction mixture obtained and to using the compound of formula (I) to produce D,L-proline.

Cyclic acetals of glutamic acid-.gamma.-semialdehyde, process for their

Process for the production of tryptophane-hydantoin

There are produced peptides by asymmetrical hydrogenation of dehydropeptides of the general formula ##STR1## in which n is a whole number from 1 to 4, R.sub.1 and R.sub.2 are the same or different, and are hydrogen, a straight or branched chain alkyl group with 1 to 10 carbon atoms, or such a group substituted with a carboxyl group, a phenyl group which is unsubstituted or substituted in the 3 or 4 position or in both the 3 and 4 positions by a hydroxyl, alkoxy, or acyloxy group or an indolyl group which is unsubstituted or substituted in the 6 position by fluorine or chlorine or an indolyl group substituted by a methyl group. R.sub.3 is hydrogen, an alkali metal, or a lower alkyl group with 1 to 4 carbon atoms, R.sub.4 is hydrogen, an acetyl group or a chloroacetyl group and R.sub.5 is hydrogen or a straight or branched chain alkyl group having 1 to 4 carbon atoms with the proviso that when n is 2, 3, or 4, the individual groups R.sub.5 are the same or different, in the presence of chiral rhodium-complexes.

Process for the production of peptides

The invention is directed to 2-[2'-(hydanto-5-yl)-ethyl]-5,5-dimethyl-1,3-dioxane of the formula ##STR1## its production by reaction of 2-(2'-formylethyl)-5,5-dimethyl-1,3-dioxane with hydrogen cyanide or a cyanide ion supplying compound, ammonia, or an ammonium ion supplying compound and carbon dioxide or a carbonate ion supplying compound in aqueous alcoholic solution and its use for the production of tryptophane-hydantoin.

2-[2'-(Hydanto-5-yl)-ethyl]-5,5-dimethyl-1,3-dioxane

A process is described for the catalytic, selective preparation of 2-vinylpyridine from acetylene and acrylonitrile using a cyclopentadienylcobalt catalyst or .pi.-allylcobalt catalyst at elevated temperature in an inert solvent, wherein the acrylonitrile concentration is up to 2 mols/liter and the reaction is carried out at a temperature over 140.degree. C. and up to 180.degree. C., the reaction time being not more than 50 minutes.

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Hanau, Germany

Marc Samson