Studies of the Organic Reaction of Metal Carbonyl. VIII. The Isomerization of Aliphatic C5- and C6-Acylcobalt Carbonyls

Abstract

Abstract The isomerization of C5-acyl(n-valeryl- and α-methylbutyryl-) and C6-acyl(n-caproyl-, α-methylvaleryl- and α-ethylbutyryl-) cobalt carbonyls has been studied and compared with that of C4- acyl(n- and isobutyryl-) cobalt carbonyls previously reported. It has been observed that solvents have great effects on the isomerization (the rate and equilibrium) of the C5-acylcobalt carbonyls. The equilibrium proportion of the isomers (iso/normal) is almost 1 in diethyl ether and tetrahydrofuran. In solvents such as dioxane, ethyl acetate and benzene it seems difficult for this isomerization to occur. α-Ethylbutyrylcobalt carbonyl appears to isomerize directly to n-caproylcobalt carbonyl. However, n-caproylcobalt carbonyl isomerizes only to α-methylvaleryl-cobalt carbonyl; the reverse isomerization also occurs, but it seems very difficult for any other isomerization between the two of them to occur.