Hoffmann-la Roche Inc.

Reinhard Zell

Erich Widmer

Hans G Leuenberger

Walter Boguth

Hans Johann Mayer

Richard Barner

Max Schmid

Emil A Broger

Yvo Crameri

Teodor Lukac

Hansjorg Grass

A novel process for the manufacture of cyclohexene derivatives which are suitable as intermediates for the manufacture of rhodoxanthin or zeaxanthin, as well as a process for the manufacture of rhodoxanthin or of zeaxanthin itself. The invention is also concerned with a novel starting material and novel intermediates in this process.

Process for the manufacture of cyclohexene derivatives

A process for the manufacture of the novel compound of the formula ##STR1## from the compound of the formula ##STR2## is described. This process comprises cathodically reducing the compound of formula I in a basic, aqueous-organic solvent mixture. The compound of formula II is an intermediate in the manufacture of rhodoxanthin or zeaxanthin.

A process for producing 3-(5-hydroxy-3-methyl-1,3-pentadienyl)-2,4,4-trimethyl-2-cyclohexen-1-one, an intermediate for canthaxanthin, by hydrogenation of 5-(2,6,6-trimethyl-3-oxo-cyclohexen-1-yl)-3-methyl-2-penten-4-yn-1-ol with zinc and a carboxylic acid.

Process for producing cyclohexenes

A process for asymmetrically hydrogenating through the use of microorganisms a double bond connected to tertiary carbon atom in an olefinic aliphatic compound to produce a tertiary, optically active aliphatic compound useful as an intermediate for optically active Vitamins E and K.

Process for the manufacture of tertiary, optically active aliphatic

The compound 6-hydroxy-3-(5-hydroxy-3-methyl-1,3-pentadienyl)-2,4,4-trimethyl-2-cyclohe xen-1-one useful as intermediate for producing the natural coloring agent astaxanthin as well as a method for synthesizing astaxanthin from this compound and synthesizing the compound from 2-hydroxyketo isophorone.

A process for fermentatively hydrogenating and reducing ketoisophorone to produce optically active [4R,6R]-4-hydroxy-2,6,6-trimethyl-cyclohexanone useful as an intermediate in the production of optically active carotenoids and intermediates in the production of these carotenoids.

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Rodersdorf, Switzerland

Reinhard Zell