Chapter 19 I Naming and Structure of Carboxylic Acids 1 Naming 19 1 A Carboxylic acid trumps other functional groups for naming 2 Structure 19 2 A C O is relatively planar OH is sp3 B Water soluble C Hydrogen bonding Dimerization II Acidity and Basicity 19 4 1 Acidity of OH B Increased acidity with presence of EWG e withdrawing groups A Resonance stabilization of conjugate base 2 Protonation of Carboxylic Acid III Industrial Synthesis of Carboxylic Acids 19 5 1 Formic acid synthesis 2 Acetic acid synthesis via ethene oxidation 3 Acetic acid synthesis via carbonylation IV Synthesis of COOHs 19 6 1 Oxidation of primary alcohols and aldehydes A CrO3 KMnO4 B Dilute HNO3 2 Addition of organometallics to CO2 s 3 Hydrolysis of Nitriles A H or B V Substitution at the carbonyl 19 7 1 COOHs and derivatives di er from ald ket in that they have a good LG 2 Attack at carbonyl goes via addition elimination mechanism substitution reaction 3 Base catalyzed add elim mechanism 4 H catalyzed pathway 5 Neutral 6 Problems with substituting COOHs A Aside from a poor LG an acidic proton exists B Acid catalyzed pathways dominate one exception is LiAlH4 VI Reactions of COOHs 1 Acyl Halides 19 8 A COOH inorganic halogenated compound B Mechanism entropy driven 2 Anhydrides A COOH acyl halide 3 Esters 19 9 A H catalyzed addition of an alcohol to COOH Fischer esteri cation B Intramolecular ester formation 4 Amide 19 10 A COOH amine heat B H catalyzed pathway is di cult C Amide formation D Intramolecular amide formation VII Other Reactions of COOHs 1 Reduction with LAH LiAlH4 19 11 2 Hell Vollhard Zelinsky reaction HVZ 19 12 A Bromonation alpha to the acid B Proceeds through an acyl halide enol precursor C Used for synthetic amino acid VIII Biological Applications 19 13 1 Fatty Acids long chain COOHs cis vs trans A Made by acetic acid coupling 2 Long chain carboxylates soaps A Form micelles 3 Natural products Chapter 20 I Reactivity and Structure of COOHs Derivatives 20 1 1 Follow typical addition elimination mechanisms Nucleophilic acyl substitutions NAS 2 Better LGs make easier reactions
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