Abstract: The present invention relates to a process for the preparation of R- and S-lipoic acid and R- and S-dihydrolipoic acid comprising (a) reaction of where MS is SO2—R? and R and R? independently of one another are C1–C6-alkyl, C3–C8-cycloalkyl, C3–C8-cycloalkylalkyl, aryl or aralkyl, with sodium sulfide and sulfur in methanol. The invention especially relates to processes for preparing pure R- or S-dihydrolipoic acid, which is either used directly or processed further to give R- and S-lipoic acid. The process also serves for the production of pharmaceuticals. The present invention further relates to a solution of sodium sulfide trihydrate and sulfur in methanol, the sulfur being present in a molar excess over the sodium sulfide trihydrate, and a kit which comprises the solution according to the invention.

Abstract: Processes for the preparation of R-lipoic acid or S-lipoic acid comprising a process step selected from a) distillation of dihydrolipoic acid, b) reaction of ?or its stereoisomer, where Ms is SO2—R? and R and R? independently of one another is [sic] C1-C6-alkyl, C3-C8-cycloalkyl, C3-C8-cycloalkylalkyl, aryl or aralkyl, with sodium sulfide and sulfur in ethanol and reaction with a complex hydride, (c) the extraction of a protic solution of R-dihydrolipoic acid or S-dihydrolipoic acid with organic solvents at a pH from 9 to 10, or (d) the extraction of R-dihydrolipoic acid or S-dihydrolipoic acid with organic solvents from a protic solution at a pH of 4 to 5, or a combination of one or more of steps (a) to (d), and processes for the preparation of dihydrolipoic acid and the compound 1,6,8 [lacuna] octanetriol.

Abstract: The present invention relates to a process for the preparation of R— and S-lipoic acid and R— and S-dihydrolipoic acid comprising (a) reaction of where MS is SO2—R? and R and R? independently of one another are C1-C6-alkyl, C3-C8-cycloalkyl, C3-C8-cycloalkylalkyl, aryl or aralkyl, with sodium sulfide and sulfur in methanol. The invention especially relates to processes for preparing pure R— or S-dihydrolipoic acid, which is either used directly or processed further to give R— and S-lipoic acid. The process also serves for the production of pharmaceuticals. The present invention further relates to a solution of sodium sulfide trihydrate and sulfur in methanol, the sulfur being present in a molar excess over the sodium sulfide trihydrate, and a kit which comprises the solution according to the invention.

Abstract: The present invention relates to the use of progesterone or a progesterone receptor agonist for the inhibition of steroid synthesis, in particular for inhibiting the expression of the steroidogenic acute regulatory protein (StAR protein).

Abstract: A process for preparing N-acyl derivatives of the formula I, in which the substituents independently of one another have the following meanings: X is CH(OR3)2, COOR3; R1 is hydrogen, C1-C12-alkyl, aryl, unsubstituted or substituted; R2 is hydrogen, C1-C12-alkyl, aryl, unsubstituted or substituted; R3 is C1-C12-alkyl, which comprises reacting a carboxamide R1—CONH2 of the formula II with a glyoxal monoacetal derivative of the formula III, in the presence of a carboxylic acid R4—COOH of the formula IV where R4=C1-C12-alkyl, where the substituents R1 to R3 are as defined above, is described.

Abstract: Processes for the preparation of R-lipoic acid or S-lipoic acid comprising a process step selected from

Abstract: A process for the preparation of 1,1,4,4-tetramethoxy-2-butene by reacting 2,5-dimethoxydihydrofuran with methanol in the presence of acids comprises carrying out the reaction in the presence of solid catalysts having acidic centers.

Abstract: Phosphonium salts are prepared by reacting an alkanol with triarylphosphine and sulfonic acids in a solvent.

Abstract: Phosphonium salts are prepared by reacting an alkanol with triarylphosphine and sulfonic acids in a solvent.

Abstract: A process for the preparation of 1,1,4,4-tetramethoxy-2-butene by reacting 2,5-dimethoxydihydrofuran with methanol in the presence of acids comprises carrying out the reaction in the presence of solid catalysts having acidic centers.

Abstract: In the 2 &THgr; diffractogram of an enantiomerically pure crystalline (R)- or (S)-lipoic acid, the most intense reflection line in the range from 13° to 30° is that at 2 &THgr;=23°.

Abstract: Phosphonium salts are prepared by reacting an alkanol with triarylphosphine and sulfonic acids in a solvent.

Abstract: A process for the preparation of 1,1,4,4-tetramethoxy-2-butene by reacting 2,5-dimethoxydihydrofuran with methanol in the presence of acids comprises carrying out the reaction in the presence of solid catalysts having acidic centers.

Abstract: A process for preparing folic acid, which comprises reacting a tetraalkoxypropanol of the general formula I, in which the substituents R are C1-C4-alkyl, with triaminopyrimidone of the formula II and p-aminobenzoyl-L-glutamic acid of the formula III

Abstract: Organosulfur compounds can be used in complexes with carotenoids for effecting a bathochromic shift in the absorption bands of carotenoids in the UV/vis spectrum. Carotenoid formulations comprising these complexes, a process for preparing these formulations and their use in the food, cosmetics and pharmaceutical sectors are described.

Abstract: Phosphonium salts are prepared by reacting an alkanol with triarylphosphine and alkyl or trifluoromethane sulfonic acids in a solvent.

Abstract: A process for preparing 4-hydroxy-1,2,2-trimethylcyclopentyl methyl ketones of the general formula I, in particular of the (1R,4S)-4-hydroxy-1,2,2-trimethylcyclopentyl methyl ketone of the formula Ia ##STR1## which is required for preparing the red dye capsorubin which is in demand, starts from 2,2,6-trimethylcyclohexanones of the general formula II ##STR2## where R is hydrogen or a protective group, via the novel intermediates of the general formulae V and VI ##STR3## by diastereoselective epoxidation and reaction of the resulting 7-oxabicyclo[4.1.0]heptanes of the general formula VIII ##STR4## with Lewis acids and, where appropriate, removal of the protective group. Also claimed are the novel intermediates of the formula V and their (1S) and (1R) isomers and those of the formula VIII as well as their (1R,3S,6S), (1S,3S,6R) and (1R,3R,6S) isomers.

Abstract: Preparing (3R, 3'R)-zeaxanthin of the formula I ##STR1## starting from (4-hydroxy-2,2,6-trimethylcyclohexanone of the formula II ##STR2## via the novel intermediates (4R,6R)-1-formyl-2,2,6-trimethyl-7-oxabicyclo[2.2.1]heptane of the formula IV ##STR3## (4R,6R)-1-(3-oxo-1-butenyl)-2,2,6-trimethyl-7-oxabicyclo[2.2.1]heptane of the formula V ##STR4## (4R,6R)-1-(3- hydroxy-3-methyl-1,4-pentadienyl)-2,2,6-trimethyl-7-oxabicyclo[2.2.1]heptan e of the formula VI ##STR5## [5-(4R,6R)-(4-hydr oxy-2,2,6-trimethyl-1-cyclohexylidene)-3-methyl-1,3-pentadienyl]triarylphos phonium salt of the formula iso-III ##STR6## where Ar is aryl and X is one equivalent of an anion of a strong acid. The (4R,6R)-1-formyl-2,2,6-trimethyl-7-oxabicyclo[2.2.1]heptane of formula IV is obtained by reacting the ketone of the formula II with dichloromethyllithium, which can be prepared by metallation of dichloromethane with butyllithium or lithium diisopropylamide.

Abstract: A process for the preparation of pure trans- and cis-4-hydroxy-2, 2,6-trimethylcyclohexan-1-one from a mixture of these isomers comprises fractionally rectifying the isomeric mixture in a suitable column having from about 30 to 80 theoretical separation stages at temperatures of preferably from 50.degree. to 130.degree. C. and a pressure in the range from 0.1 to 5 mbar. The products are essential intermediates for the preparation of 3-hydroxycarotenoids such as cryptoxanthin and zeaxanthin.

Abstract: A process for preparing polyenecarbonyl compounds having a high all-E content and their acetals or ketals by aldol condensation or Horner-Emmons reaction comprises carrying out the reaction, for the purposes of the preferred formation of a double bond of E configuration and in order to maintain the E configuration of the double bonds in the stating compounds as completely as possible, in the presence of oxygen or an oxygen-inert gas mixture or nitric oxide or a nitric oxide-inert gas mixture and/or in the presence of specific stable radicals and/or in the presence of quinones or quinone derivatives.