A highly selective catalytic, one-step synthesis converts oleic acid into 9(10)-carboxystearic acid in high yields (85-99%). Hydrocarboxylation with water and carbon monoxide under pressure (3000-4000 psi)
Hydroformylation of methyl linoleate and linolenate with a rhodium-triphenylphosphine catalyst yields 1,4diformyl esters as major products and 1,3-diformyl esters as minor products. Unsaturated and saturated monoformyl esters are also produced from both substrates and triformyl esters from methyl linolenate. Conjugated methyl linoleate produces mainly monoformyl esters, whereas methyl c/s-9,c/s-l 5-octadecadienoate produces diformyl esters. The mechanism postulated for dihydroformylation involves cyclic unsaturated acyl-rhodium-triphenylphosphine complexes controlling the position of the second formyl group. These intermediates are also implicated in double-bond hydrogenation and isomerization which accompany dihydroformylation. The polyformyl ester products formed contrast with the monoformyl ester products obtained when cobalt carbonyl catalysts are used.
Soybean, safflower and linseed oils and their methyl esters were effectively hydroformylated with a rhodium and triphenylphosphine catalyst system. The product from safflower methyl esters, hydroformylated at 100 C and 1000 psi synthesis gas (H2 + CO), proved to be a mixture of formylstearate, formyloleate and diformylstearate. At 150 C and 15 00 psi synthesis gas the formyloleate was hydrogenated and the product formed was a mixture of mono‐ and diformylstearates. The unsaturated monoformyl fraction (100 C) was tentatively identified as a mixture consisting mainly of methyl 9(10)‐formyl‐cis‐12‐and methyl 12(13)‐formyl‐cis‐9‐octadecenoates. The saturated monoformyl fraction (150 C) was a more complex isomeric mixture of methyl formylstearate. The diformyl fractions from hydroformylated safflower and linseed esters were identified as mixtures consisting mainly of 9,12‐(10,13)‐ and 10,12‐(11,13)‐diformyloctadecanoates. When hydroformlyation of polyunsaturated fats was interrupted,cis‐unsaturated formyl oils resulted.
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