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US 4,435,585 AGranted
Process for the preparation of dihydrocinnamaldehyde derivatives
AssigneeGivaudan SA
InventorsYvo Crameri, Paul A. Ochsner, Peter Schudel
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Abstract
There is disclosed a novel process for preparing a number of cinnamaldehyde derivatives. These cinnamaldehyde derivatives can be reduced to dihydrocinnamaldehyde derivatives, a number of which are commercially important in the preparation of fragrances. The invention is also directed to a number of novel intermediates and their preparation.
Claims8
A process for the manufacture of a compound of the formula ##STR5## wherein:
- R.sup.1 represents isopropyl, n-butyl, sec. butyl, isobutyl, tert. butyl, methoxy or, together with R.sup.2, represents methylene dioxy;
- R.sup.2 represents hydrogen or, together with R.sup.1, represents methylenedioxy;
- and
- R.sup.3 represents hydrogen or methyl which comprises:
- (a) converting a ketone of the formula ##STR6## to the corresponding ketal ##STR7## wherein R.sup.4 is methyl or ethyl;
- (b) converting said ketal by means of an alcohol cleavage, to the corresponding enol ether ##STR8## (c) converting said enol ethers to the corresponding .beta.-alkoxy aldehyde ##STR9## by means of a hydroformylation reaction, and (d) subjecting said .beta.-alkoxy aldehyde to an alcohol cleavage,
- wherein the hydroformylation is carried out by reacting said enol ether with carbon monoxide and hydrogen in the presence of a rhodium catalyst wherein:
- (a) the ratio of carbon monoxide to hydrogen is between 1 to 4 and 4 to 1;
- (b) the temperature is between 50.degree. C. and 150.degree. C;
- and
- (c) the pressure is between 150 and 700 atmospheres.
8 more elements
A process for preparation of .beta.-alkoxy dihydrocinnamaldehyde of the formula ##STR10## wherein:
- R.sup.1 represents isopropyl, n-butyl, sec. butyl, isobutyl, tert. butyl, methoxy or, together with R.sup.2, represents methylene dioxy;
- R.sup.2 represents hydrogen or, together with R.sup.1, represents methylene dioxy;
- R.sup.3 represents hydrogen or methyl;
- and
- R.sup.4 represents methyl or ethyl
- which comprises reacting a compound of the formula ##STR11## with carbon monoxide and hydrogen in the presence of a rhodium catalyst wherein
- (a) the ratio of carbon monoxide to hydrogen is between 1 to 4 and 4 to 1,
- (b) the temperature is between 50.degree. C. and 150.degree. C., and
- (c) the pressure is between 150 and 700 atmosphere.
6 more elements
Dependencies are inferred from the claim text.