Novartis Ag

Imperial Chemical Industries Limited

Degussa Aktiengesellschaft

Sandoz Gmbh

Basf Aktiengesellschaft

Hoffmann-la Roche Inc.

Degussa - Huls Ag

Dieter Seebach

Roland M Wenger

Pietro Bollinger

Hans Kobel

Brigitte Besemer-Rosenwirth

Soo Young Ko

Karlheinz Drauz

Matthias Kottenhahn

Rene P Traber

Axel Griesbeck

Rene Imwinkelried

Karl Siemensmeyer

Frank Meyer

Michael Schwarm

Hermann Lotter

Hans G Leuenberger

Peter Karl Matzinger

Ren&eacute;P Traber

Reto Naef

Theodor Weber

Max F Zuger

Hans-Georg Kuball

Bernhard Weiss

Adrian Thaler

Thomas Muller

Peptides

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.

TADDOL and titanium ( ) taddolate dendrimers and composition

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.

Cyclosporin fermentation process

Taddol and titanium (IV) taddolate dendrimers

Chiral compounds

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. The amidine based system lends itself to the manufacture of complex esters, gentle splitting of peptides from the carrier, gentle saponification of amides or esters.

Transesterification and other conversion reactions of acid derivatives,

Cyclosporins

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.

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.

Method of producing optically active 1,3-imidazolidine-4-ones

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.

Optically active B hydroxy acids

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.

Process for preparing (S)-4-methyl-.beta.-butyrolactone

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.

2-Substituted-6-methyl-1,3-dioxan-4-one

Process for stereosectively preparing optically active compounds

Cylosporins e.g. of formula II ##STR1## in which X is -MeBmt- or -dihydro-MeBmt- and

Novel cyclosporins

.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.

Process for the enantioselective production of

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Zurich, Switzerland

Dieter Seebach