thyroxine

Place syntheses below

I can see how high energy uv light ligh and oxygen might oxidize the alpha carbon to a ketone, and I understand the reductive amination, but I don't understandteh coupling reaction. I didn't find it on wikipedia either. Is this a biosynthesis or an actual test tube synthesis? Bruce Bondurant This is not the biosynthesis, we can obtain it from here though. This is the mechanism of non-enzymic synthesis from diiodotyrosine and its keto acid derivative. Work Cited: http://onlinelibrary.wiley.com/doi/10.1111/j.1432-1033.1968.tb00360.x/pdf