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US 4,051,174 AGranted
Isomerization process
AssigneeHoffmann-La Roche Inc.
InventorsHansjorg Stoller, Hans Peter Wagner
Life of this patent
Estimating the term…
Abstract
A process for isomerizing vitamin A and derivatives thereof utilizing either palladium or a palladium containing compound as a catalyst.
Claims15
A process for geometrically isomerizing an isomeric composition selected from the group consisting of 9-cis and 11-cis isomers of a compound of the formula:
- ##STR2## --COOR.sub.2, --CONHR.sub.3 or --CON(R.sub.3).sub.2 ;
- R is lower alkoxy or the two R's taken together form lower alkylenedioxy;
- R.sub.1 is alkanoyl or aroyl;
- R.sub.2 is alkyl, aryl or aralkyl;
- and R.sub.3 is hydroxy, alkyl, aryl or aralkyl;
- mixtures thereof, or mixtures thereof with the all trans isomer of said compound comprising contacting at a temperature of from 0.degree. C to 250.degree. C, said composition in an inert solvent medium with a palladium compound catalyst where the palladium compound is other than palladium phthalocyanin or other than a palladium compound containing a cyanide ion and producing a geometric isomeric mixture of said composition from which the all trans isomer can be separated therefrom in pure form by crystallization.
3 more elements
Dependencies are inferred from the claim text.