GB875713A - Polyene carboxylic acids and esters thereof and a process for the manufacture of same - Google Patents

Abstract

The invention comprises compounds of formula I wherein n = O, and a process for the manufacture of compounds of formula I wherein n is 0, 1, 2 or 3 and R (reading from left to right) is the methyl group and is only present in the parenthetical fragments corresponding to the first and third extensions of the chain. <FORM:0875713/IV (b)/1> by converting the phosphonium salt (II) into the corresponding phosphorane, condensing the latter with Vitamin A aldehyde, splitting off triaryl-phosphine oxide from the so formed adduct (e.g. by heating) and, if required, hydrolysing the ester obtained. Such compounds (I) are used as additives for poultry feeds for pigmentation of the egg yolk, circulation, beak, skin, fat and flesh. <FORM:0875713/IV (b)/2> The phosphonium salts (II) may be obtained by condensation of halogenocarboxylic esters, e.g. an a -haloacetic acid ester or a g -halotiglinic acid ester, with a triaryl phosphine in an inert solvent, e.g. benzene. Two suitable halogenoesters are stated to be novel and may be prepared as follows. Reaction of methyl b -acetylacrylate with lithium acetylide and hydrogenation of the product (after decomposition with ammonium chloride) with Pb-inhibited Pd catalyst gives 1-methoxycarbonyl-3-methyl - 3 - hydroxypentadiene-(1:4), which with PBr3 gives 1-methoxycarbonyl-3-methyl-5-bromopentadiene-(1:3); hydrogenation p (same catalyst) of the tetrahydropyranyl ether of the said pentadiene-(1:4) derivative in presence of quinoline and reduction of the product with LiAlH4, followed by oxidation with MnO2 in petroleum ether, gives 4-methyl-4-(tetrahydro-pyranyloxy) - hexadiene - (2:5) - al - 1, which affords 1 - methoxycarbonyl - 1:5 - dimethyl-7-bromoheptatriene-(1:3:5) by reaction with (1-methoxycarbonylethylidene) - triphenyl phosphorane followed by hydrobromic acid. Examples are given of the production of 2,6,11,15 - tetramethyl - 17 - [21,61,61-trimethyl-cyclohexen -1-yl]-heptadecaoctaen-(2,4,6,8,10,12, 14,16)-oic-1 acid methyl ester and 5,9-dimethyl-11 - [21,61, 61-trimethylcyclohexen-1-yl]-undecapentaene-(2,4,6,8,10) -oic-1-acid methyl ester by reacting [3 - methyl-7-methoxycarbonyl-octatriene - (2,4,6) - ylidene]-triphenyl phosphorane and methoxycarbonylmethylene-triphenyl phosphorane respectively with Vitamin-A aldehyde. The hydrolysis of the product of the first example to the corresponding acid is also described.ALSO:The invention comprises a process for the manufacture of compounds of the formula indicated, wherein n is 0, 1, 2 or 3 and R (reading from left to right) is the methyl group and is only present in the parenthetical fragments corresponding to the first and third extensions of the chain, (see Group IV(b)). <FORM:0875713/I/1> The compounds are useful as additives for poultry feeds for pigmentation of the egg yolk, circulation, beak, skin, fat and flesh.ALSO:The invention comprises a process for the manufacture of compounds of the formula indicated, wherein n is 0, 1, 2 or 3 and R (reading from left to right) is the methyl group and is only present in the parenthetical fragments corresponding to the first and third extensions of the chain (see Group IV (b)) <FORM:0875713/VI/1> The compounds are useful as colouring materials for foodstuffs.