Csir

Aeci Limited

Stephanus Francois Marais

Neil Stockenstrom Gardiner

Christopher John Parkinson

Jennifer Ann Chaplin

Dean Brady

Lucia H Steenkamp

Etienne Van Eeden Skein

Robin Kumar Mitra

Shavani Reddy

Deborah Nicole Davidson

Dana Helen Braithwaite

Madrie Portwig

Owen Lungile Njamela

Melanie Daryl Evans-Dickson

Thebeeapelo John Khaile

Butana Andrew Mboniswa

Christa Maria Jungmann

A process of separating a single desired stereoisomer from a racemic mixture of eight stereoisomers of a compound of formula (III), wherein Rrepresents an isopropanol group, an isopropyl group or an isopropylene group, includes the steps of: contacting the racemic mixture in a suitable organic solvent with an esterifying agent and a stereospecific enzyme which stereoselectively esterifies the &#x2014;OH group of the desired stereoisomer, for a time sufficient to convert a desired percentage of the desired stereoisomer to a compound of formula (IV), wherein Ris as defined above and Ris an alkyl or an aryl group, to give a first reaction product including the compound of formula (IV), the organic solvent, the unconverted stereoisomers of the compound of formula (III), excess esterifying agent and by-products of the reaction; and separating the compound of formula (IV) from the first reaction product. The process is of particular application for the production of (&#x2212;)-menthol

Process for preparing (-) menthol and similar compounds

A process for the production of disubstituted propionic acid derivatives which are intermediates in the synthesis of .alpha.-arylpropionic acids such as naproxen, involves the reaction of a naphthalene derivative such as 2-methoxynaphthalene, with an alkylating agent such as an alkyl pyruvate in the presence of a catalyst, and then dehydrating and hydrogenolising, or directly hydrogenolising, or derivatising and then hydrogenolising the product thereof, to produce the desired compound.

Synthesis and resolution of propionic acid derivatives

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Garsfontein, South Africa

Stephanus Francois Marais