CHEM 313 Chapter : Chem_313_PS9_2014_v1.pdf
Document Summary
Chem 313 problem set #9, 2014: show how thiamin can be used to produce benzoin, and describe the similarities and differences between this reaction and the classical (cn catalyzed) conditions. Nh2: shown below is a stetter catalyst (a biomimetic of thiamin). Oh for how this catalyst yields the given product from the starting materials: thiaminases degrade thiamin into separate thiazole and pyrimidine moieties. Thiaminase i has been associated with early mortality syndrome in predatory fish of the laurentian great lakes and the new york finger lakes as well as in atlantic salmon in the baltic sea. Give the mechanism of thiamin degradation, starting with cysteine as nucleophile (1,2 addition on double bond where the resulting negative charge is stabilized, followed by e1cb elimination). Mechanism-based inhibitors of such thiamin-dependent decarboxylases are rare. There are several instances where phosphonate analogues of 2-keto acids have proved to be effective.
