Hoffmann-la Roche Inc.

Roche Vitamins Inc.

Theodor Siegfried

Bruno Burdet

Jean-Marie Santer

August Ruttimann

Rudolf Schmid

Emil A Broger

Yvo Crameri

August Ru/ Ttimann

August R Uttimann

Peter Fahrni

Novel processes and intermediates useful for the manufacture of the Wittig ester salts are disclosed. The Wittig ester salts are known as important C.sub.5 building blocks for the manufacture of various polyenecarboxylic acid esters in the field of carotenoid chemistry.

Method for the production of (3-alkoxycarbonyl-2-butenyl)

A processes and intermediates useful for the manufacture of the Wittig ester salts are disclosed. The Wittig ester salts are known as important C.sub.5 building blocks for the manufacture of various polyenecarboxylic acid esters in the field of carotenoid chemistry.

The present invention is concerned with a process for the manufacture of optically active compounds of the formula ##STR1## wherein R signifies lower alkyl, lower alkoxy, phenyl, benzyl or --NR.sub.2.sup.1, R.sup.1 signifies lower alkyl, phenyl, benzyl or hydrogen and * signifies an optically active center, by asymmetrically hydrogenating an enol derivative of ketoisophorone of the formula ##STR2## wherein R has the significance given above, in the presence of a rhodium complex of an optically active diphosphine ligand.

Process for the enantioselective hydrogenation of ketosiophorone

Novel processes and intermediates useful for the manufacture of the Wittig ester salts are disclosed. The Wittig ester salts are known as important CS building blocks for the manufacture of various polyenecarboxylic acid esters in the field of carotenoid chemistry.

Method for the production of

A process for the manufacture of ascorbic acid from 2-ketogulonic acid esters (KGAE) utilizing amine salts of the latter is disclosed.

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Riehen, Switzerland

Theodor Siegfried