CAS CH 203 Lecture Notes - Lecture 27: Aldol Reaction, Claisen Condensation, Thiamine Pyrophosphate
Document Summary
Review of electrophiles and nucleophiles found in biochemistry. C-c bond formation via carbonyl chem (aldol and claisen reactions): aldehydes, ketones, and coenzyme. Prenyl transfer reactions (will not be covered in 5. 07) Redox cofactors flavins (fad, fmn, riboflavin) and nad+ (nadp+) 35-37: review of electrophiles and nucleophiles in biology. 2: carbonyl chemistry: mechanisms of c-c bond formation. The aldol and claisen reactions involve carbonyl chemistry. These reactions are prevalent in glycolysis, fatty acid biosynthesis and degradation and the pentose phosphate pathway: aldol reaction generalizations: a. b. c. All aldol reactions occur with retention of configuration. Activation by imine formation with a lysine in the active site (class i aldolases found in eucaryotes) a: use of zn2+ (class ii aldolases found in procaryotes) The increase in acidity at the a hydrogens involves two mechanisms: In addition, the c of is activated by both mechanism (a. ) and (b. ) for nucleophilic attack. Coenzyme a (red = phosphopantetheine prosthetic group: claisen reaction generalizations:
