THE suggestion that thyroxine might be formed in Nature from tyrosine through the stage of diiodotyrosine was made at an early stage of the elucidation of the chemistry of thyroxine, and was made ...

The procedure summarized below, and which involved the synthesis of N-acetyl-tyrosine and N-acetyl-3 : 5-diiodotyrosine as intermediates, was finally adopted. All compounds were hence labelled in ...