A hydroxyethyl derivative of this compound is a common intermediate in the synthesis of valine, leucine, and isoleucine. The transketolase activity of red blood cells is studied to measure the deficiency of this compound whose pyrophosphate form is a coenzyme used to decarboxylate pyruvate to form Acetyl CoA. In alcoholics its deficiency results in Wernicke-Korsakoff syndrome, while a more common 
A hydroxyethyl derivative of this compound is a common intermediate in the synthesis of valine, leucine, and isoleucine. The transketolase activity of red blood cells is studied to measure the deficiency of this compound whose pyrophosphate form is a coenzyme used to decarboxylate pyruvate to form Acetyl CoA. In alcoholics its deficiency results in Wernicke-Korsakoff syndrome, while a more common deficiency of it originally resulted from a switch to polished rice. Sometimes called aneurin, it consists of a pyrimidine and a thiazole ring, and that structure was correctly described by Casimir Funk. For 10 points, identify this vitamin, whose deficiency causes beriberi.
A hydroxyethyl derivative of this compound is a common intermediate in the synthesis of valine, leucine, and isoleucine.
thiamine [or B1]