Abstract: The invention provides novel &bgr;-peptides comprising 2 or more different &bgr;-amino acid residues, preferably compounds of formula I 1

Abstract: The invention provides novel &bgr;-peptides comprising 2 or more different &bgr;-amino acid residues, preferably compounds of formula I wherein the R residues, X and n are as defined. Compounds of the invention having as few as 5 or 6 &bgr;-amino acid residues exhibit stable structures in solution and the compounds generally exhibit good resistance to proteolytic degradation. The compounds of the invention provide a valuable new source of structural diversity for synthesis of biologically active compounds, e.g. for pharmaceutical uses.

Abstract: TADDOL dendrimers are described. Their use as crosslinkers in polymerisation reactions and the use of Ti salts of polymer-bound TADDOL dendrimers as catalysts in enantioselective addition reactions is disclosed.

Abstract: It has been found that nonimmunosuppressive, cyclophilin-binding cyclosporins are useful in the treatment and prevention of AIDS and AIDS-related disorders. Such cyclosporins include novel Ciclosporin derivatives modified at the 4- and/or 5-positions.

Abstract: TADDOL dendrimers are described. Their use as crosslinkers in polymerisation reactions and the use of Ti salts of polymer-bound TADDOL dendrimers as catalysts in enantioselective addition reactions is disclosed.

Abstract: Chiral compounds of the formula I ##STR1## where: R.sup.1,R.sup.2,R.sup.3,R.sup.4 are hydrogen or aromatic, aliphatic or araliphatic radicals having 1 to 40 carbon atoms,R.sup.5,R.sup.6,R.sup.7,R.sup.8 are aromatic or aliphatic radicals having 1 to 20 carbon atoms,with the proviso that at least one of the radicals R.sup.1 to R.sup.8 contains a polymerizable group,are used as dopes in liquid crystals, in compositions for coating substrates and in the preparation of interference pigments which can be used in printing inks and surface coatings.

Abstract: A process employs amidine or amidine base and a metal compound in the presence of an alcohol or water to transesterify, or saponify esters or amides. Since the process employs relatively mild conditions, it is especially suitable for the production of optically active substances and biomolecules, e.g. peptides, amino acids and nucleic acids which are sensitive to elevated temperatures, extreme pH values and/or long reaction times since these compounds are easily racemised or denatured. The conditions additionally find use in solid phase systems. When amino acid or peptide esters are saponified, the splitting is brought about with lithium hydroxide alone under mild conditions. The use of an amidine base, more particularly DBU or DBN, in combination with the metal salt additionally accelerates the reaction so strongly that even sensitive acid derivatives can be reacted under mild conditions.

Abstract: It has been found that nonimmunosuppressive, cyclophilin-binding cyclosporins are useful in the treatment and prevention of AIDS and AIDS-related disorders. Such cyclosporins include novel Ciclosporin derivatives modified at the 4- and/or 5-positions.

Abstract: Nonimmunosuppressant cyclosporin derivatives having cyclophilin-binding activity, for example, the compound, ?MeIle!.sup.4 -ciclosporin, are useful in inhibiting HIV-1 replication in treating AIDS and AIDS related disorders.

Abstract: 2.2. 1,3-imidazolidine-4-ones having the General Formula: ##STR1## are obtained in a pure form especially by means of precipitation, in which production an optically active acid can be used at 0.5-0.8 eq. for the separation of racemates. The non-desired enantiomer can be racemized in an inert solvent and the cyclization to imidazolidinone can take place by means of the optically active acid, whereupon the separation of racemates takes place directly thereafter. 1,3-imidazolidine-4-ones are valuable educts for the preparation of branched or unbranched, proteinogenic or non-proteinogenic .alpha.-amino acids by means of diastereoselective alkylation and subsequent ring splitting.

Abstract: An aldehyde (R.sup.1 CHO) and optically active 3-hydroxybutyric acid (CH.sub.3 CH(OH)CH.sub.2 COOH) are reacted to form an optically active dioxanone. This dioxanone is reacted with a compound R.sup.2 --X to form an intermediate (R.sup.1 R.sup.2 CHOCH(CH.sub.3) CH.sub.2 COOH) which is then subjected to elimination to form an optically active secondary alcohol (R.sup.1 R.sup.2 CHOH) in good yield and purity.

Abstract: The present invention relates to chemical compounds and in particular to substituted dioxanones obtained from (R)-3-hydroxybutyric acid. This invention also relates to a method for the production of such dioxanones and to processes using such dioxanones as starting-materials.

Abstract: Novel substituted dioxanones obtained from (R)-3-hydroxybutyric acid, for example 2,2-dimethoxy-6-methyl-1,3-dioxan-4-one, a method for their preparation and processes using the dioxanones as starting material. The dioxanones can be used in particular as intermediates in the preparation of (S)-4-methyl-.beta.-butyrolactone.

Abstract: An aldehyde (R.sup.1 CHO) and optically active 3-hydroxybutyric acid (CH.sub.3 CH(OH)CH.sub.2 COOH) are reacted to form an optically active dioxanone. This dioxanone is reacted with a compound R.sup.2 --X to form an intermediate (R.sup.1 R.sup.2 CHOCH(CH.sub.3) CH.sub.2 COOH) which is then subjected to elimination to form an optically active secondary alcohol (R.sup.1 R.sup.2 CHOH) in good yield and purity.

Abstract: Fluorinated nitroalcohols of the formula (I) ##STR1## process for their preparation by reaction of fluoronitroalkane of the formula (II) ##STR2## with a carbonyl compound of the formula (III) ##STR3## fluorinated aminoalcohols of the formula (IV) ##STR4## and a process for their preparation by hydrogentation of compounds of the formula (I).

Abstract: Cylosporins e.g. of formula II ##STR1## in which X is -MeBmt- or -dihydro-MeBmt- andY is -.alpha.Abu-, -Thr-, -Val- or -Nva-,wherein the residue at the 3-position, i.e. the residue Z in formula II, is an optically active, .alpha.-N-methylated .alpha.-amino acid residue of the (D)-configuration, possess pharmaceutical, in particular immunosuppressive, anti-inflammatory and anti-parasitic activity, Intermediate cyclosporin poly-anions having a de-protonated sarcosyl residue at the 3-position, e.g. polyanions of cyclosporins of formula II above wherein X and Y have the meanings given above and Z is -Sar-, in which the said residue Z is de-protonated, are also novel and part of the invention.

Abstract: .alpha.-Vinyl-.alpha.-aminocarboxylic acids of the general formula: ##STR1## where * indicates a center of asymmetry and R is hydrogen, deuterium, lower alkyl, allyl, benzyl, or benzyl substituted 1 to 3 times by alkyl, alkoxy, fluorine or chlorine and produced enantioselectively from L-methionine by a multistep process.

Abstract: The manufacture of optically active compounds of the formula ##STR1## wherein R.sup.1 signifies alkyl, phenyl or benzyl and R.sup.2 signifies hydrogen or a customary ester residue,by the fermentative reduction of compounds of the formula ##STR2## wherein R.sup.1 and R.sup.2 have the above significance. The compounds obtained are valuable intermediates in organic syntheses.

Abstract: Cyclosporins e.g. of formula II ##STR1## in which X is -MeBmt- or -dihydro-MeBmt- andY is -.alpha.Abu-, -Thr-, -Val- or -Nva-,wherein the residue at the 3-position, i.e. the residue Z in formula II, is an optically active, .alpha.-N-methylated .alpha.-amino acid residue of the (D)-configuration, possess pharmaceutical, in particular immunosuppressive, anti-inflammatory and anti-parasitic activity. Intermediate cyclosporin poly-anions having a de-protonated sarcosyl residue at the 3-position, e.g. polyanions of cyclosporins of formula II above wherein X and Y have the meanings given above and Z is -Sar-, in which the said residue Z is de-protonated, are also novel and part of the invention.

Abstract: .alpha.-Alkylated, acyclic .alpha.-aminocarboxylic acids of the formula ##STR1## where * represents a center of asymmetry, R.sup.1 is a lower alkyl, allyl, benzyl or substituted benzyl group and R.sup.2 is a lower alkyl, methoxymethyl, lower alkylmercaptoethyl, phenyl, phenyl substituted with alkyl or alkoxy, benzyl, or benzyl substituted with alkyl, alkoxy or halo are produced by an enantio-selective plural step process from the corresponding .alpha.-aminocarboxylic acid monomethyl or monoethyl amide. A particular advantage of the new process is that there can be produced from one educt-enantiomer, i.e. from an (S)- or an (R)-.alpha.-aminocarboxylic acid, selectively depending on the reaction conditions used the two enantiomeric forms of the desired .alpha.-alkyl-.alpha.-aminocarboxylic acid.