A concise synthesis of thyroxine (T4) and 3,5,3'-Triiodo-L-thyronine (T3)

Article abstract of DOI:10.1016/S0040-4039(97)01665-1

The mono- and di-iodo derivatives of 1-oxaspiro[2,5]bicycloocta-4,7-dien-6-one, 8 and 9, reacted readily with 3,5-diiodo-L-tyrosine at pH 8.0 to give 3,5,3'-triiodo-L-thyronine (T₃) and thyroxine in 70% and 94% yields respectively. In turn, 8 and 9 were prepared by the sodium bismuthate oxidation of their corresponding iodinated p-hydroxybenzyl alcohol derivatives, 6 and 7 in 32% and 37% yields.