Hoffmann-la Roche Inc.

Roche Vitamins Inc.

Robert K Muller

Hans Johann Mayer

Kurt Bernhard

Heinz Schneider

Robert Spruijtenburg

A process for the production of a Mannich reagent comprises reacting formaldehyde, especially paraformaldehyde, with a secondary amine in the complete or almost complete absence of a solvent. An alternative comprises reacting a diaminomethane produced from a secondary amine, formaldehyde, especially paraformaldehyde, as well as water with one another in about equimolar amounts. The invention is also concerned with a process for the aminomethylation of .delta.-tocopherol or of tocopherol mixtures containing this and comprises using a Mannich reagent which has been produced in the above manner. After completion of this aminomethylation process excess Mannich reagent can be separated by distillation and can be reacted with water and formaldehyde, especially paraformaldehyde, in order to regenerate further Mannich reagent suitable for use in the aminomethylation, this regeneration representing a further aspect of the invention. Finally, the invention includes certain novel bis(aminomethyl)-.gamma.-tocopherols.

Aminomethylation of tocopherols

A silyl-enol ether of the formula ##STR1## wherein n stands for the number and X stands for a group ##STR2## or n stands for the number 1 and X stands for the 6,11-dimethylhexadeca-2,4,6,8,10,12,14-heptaene-2,15-diyl group, the symbols R.sup.1 have the same or different significances and denote alkyl groups, and the symbol R.sup.2 represents a trialkylsiloxy group --OSi(R.sup.1).sub.3 or an ether group, is oxidized with percarboxylic acid and, if desired, the resulting .alpha.-siloxy ketone is hydrolyzed to an .alpha.-hydroxy ketone. This process is especially suitable for the manufacture of astaxanthin.

Cyclohexenone derivatives and process for making same

The compound 5[4(acyloxy or protected hydroxy-3-oxo-2,6,6-trimethyl-cyclohex-1-en-1-yl)-3-methyl-penta-1,4-dien- 3-ol], an intermediate for the coloring agent astaxanthin, its conversion to astaxanthin and its preparation from 4-oxo-.beta.-ionone including intermediates in this synthesis.

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Basel, Switzerland

Robert K Muller