Catalytic hydrogenation
AssigneeHoffmann-La Roche Inc.
InventorEmil A. Broger
Life of this patent
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Abstract
Compounds of the formula: ##STR1## wherein R.sup.1 is a 2,6,6-trimethyl-1-cyclohexen-1-yl or 2,3,6-trimethylphenyl group, either of which may be unsubstituted or substituted by a hydroxy group or a protected hydroxy group, R.sup.2 is aryl, and X.sup.- is an anion are manufactured by hydrogenating a compound of the formula: ##STR2## wherein R.sup.1, R.sup.2 and X.crclbar. are as above, in an organic solvent or aqueous-organic solvent in the presence of a nickel-, palladium-, platinum-, cobalt-, rhodium-, iridium-, or ruthenium-containing catalyst. The process is suitable as an intermediate step in carotenoid and retinoid syntheses.
Claims24
A process for producing a compound of the formula:
- ##STR9## wherein R.sup.1 is 2,6,6,-trimethyl-1-cyclohexen-1-yl or 2,3,6-trimethylphenyl, either of which is unsubstituted or substituted with hydroxy or a protected hydroxy group;
- R.sup.2 is aryl and X.sup..crclbar. is an anion,
- which process comprises selectively hydrogenating a compound of the formula:
- ##STR10## wherein R.sup.1, R.sup.2 and X.sup..crclbar. are as above, said compounds I and II being in any of their various cis and trans sterioisomeric forms and mixtures thereof, in an organic solvent in the presence of a catalyst which is a metal or metal compound, said metal being nickel, palladium, platinum, cobalt, rhodium, iridium or ruthenium.
A process for producing a compound of the formula:
- ##STR11## wherein R.sup.1 is 2,6,6-trimethyl-1-cyclohexen-1-yl, 2,3,6-trimethylphenyl, 4-hydroxy-2,6,6-trimethyl-1-cyclohexen-1-yl, or 4-methoxy-2,3,6-trimethylphenyl;
- R.sup.2 is phenyl and X.sup..crclbar. is chloride or bromide;
- which process comprises selectively hydrogenating a compound of the formula:
- ##STR12## wherein R.sup.1, R.sup.2 and X.sup..crclbar. are as above, said compounds I and II being in any of their varios cis and trans stereoisomeric forms and mixtures thereof, in an organic solvent in the presence of catalytic amounts of Raney-nickel.
Dependencies are inferred from the claim text.