The manufacture of polyene aldehydes and novel polyene aldehydes

摘要

The invention comprises polyene aldehydes of the general formula : in which n stands for a whole number from 2 to 7 and in which R alternately stands for the methyl group or a hydrogen atom (commencing with the methyl group reading from left to right) and of the general formula : in which n stands for 2, 4, 5, 6 or 7 and in which R alternately stands for the methyl group or a hydrogen atom (commencing with the methyl group reading from left to right) and a process for the production of polyene aldehydes which comprises acetalising in a manner known per se are aldehyde of the general formula : wherein the broken line represents an optional bond, n stands for a whole number from 1 to 6 and R alternately stands for the methyl group and a hydrogen atom (commencing with the methyl group reading from left to right) condensing the resulting acetal for even n values with a propen-(2)-yl-(3) alkyl ether or for odd n values with a vinyl ether in the presence of an acidic condensing agent in each case and treating the resulting condensation product with an acidic agent. The dots in the formulae given denote the CH3, CH2 or CH group or a carbon atom according to whether they are associated with one, two, three or four bonds. The first step of the process may be carried out by reacting the aldehyde starting material with an orthoformic acid ester in the presence of an acid catalyst, e.g. phosphonic or p-toluene sulphonic acid. The second step may be carried out in the presence of an inert solvent and an acidic condensing agent such as zinc chloride or boron trifluoride etherate. The third step of the process may be carried out with aqueous organic and inorganic acids, e.g. acetic acid, p-toluene sulphonic acid or salts such as zinc chloride and sodium bisulphate. Examples are furnished wherein the acetalisation in the first step is effected with orthoformic ethyl ester and in the second step vinyl ethyl ether or propenyl ethyl ether is employed. The specific aldehydic starting materials employed are those of the third formula above in which n is 1 and all the multiple linkages in the side chain are ethylenic or n is from 1 to 6 and the acetylenic linkage is present. 13 - [21,61,61 - trimethyl - cyclohexen - (11) - yl] - 2,7,11 - trimethyl - tridecapentaen - (2,6,8, 10,12) - yn-(4)-al-(1) is prepared by condensing an acetal of 2-methyl-penten-(2)-yn-(4)-al-(1) in a Grignard reaction with 8-[21,61,61-trimethyl-cyclohexen-(11) -yl]-2,6-dimethyl-octatrien-(2,4,6)-al-(1) and treating the condensation product with an acid. Specification 845,819 is referred to.ALSO:Poultry feeding stuffs comprise as additives for the purpose of yolk, beak, fat and flesh pigmentation aldehydes of the general formula: and which contain about 30 carbon atoms and in which n stands for a whole number from 2 to 7 and in which R alternately stands for the methyl group or a hydrogen atom (commencing with the methyl group reading from left to right) (see Group IV(b)). Specification 845,819 is referred to.