Formation of unusual side-products from succinimidyl esters of fatty acids during the acylation of amino acids

A new side-product, succinohydroxamic decanoic anhydride, was isolated from the reaction mixture during the acylation of lysine by succinimidyl decanoate in the presence of aqueous sodium hydroxide. Laurie and palmitic acid derivatives were also obtained. It is shown that these compounds can be used for acylation of amino acids. The hydroxamic acid derivatives were also detected when the acylations by succinimidyl esters of fatty acids were carried out under anhydrous conditions. Preparation of N-lauroyl-L-tyrosine methyl ester from tyrosine methyl ester and succinimidyl laurate is also described.