Organic Chemistry Chapter 10 Part I Carboxylic Acids and Their Derivatives (Ester) Nanoplasmonic Research Group

Carboxylic Acids (General) carboxyl group three ways to represent a carboxylic acid acid derivatives Organic Acids characterized the presence of a carboxylic group Bronsted-Lowry acids: Proton donors Salts or Anions: Carboxylates

Nomenclature In IUPAC nomenclature: carboxylic acids have an -oic acid suffix In common nomenclature, the suffix is usually -ic acid

Physical Properties of Carboxylic Acids Polar and form hydrogen bonds with each other At high T, in vapor phase, carboxylic acids usually exist as dimeric pairs Water solubility: Chain-length dependent

Acidity of Carboxylic Acids The acidity can be explained by either the stability of the acids or the stability of the conjugate base using inductive effect or resonance effect The stability of the acids: Inductive effect The stability of the conjugate base: Both

Synthesis of Carboxylic Acids Oxidation of Primary Alcohols and Aldehydes Hydrolysis of Nitriles, Esters, or Amides with The Addition of Acid or Base Roles of Acid or Base !!!!!! (page 298, 10.15) Reaction of Grignard Reagents with Carbon Dioxide

Carboxylic Acids Derivatives (Ester) The R part of the -OR groups is named first , followed by the name of the acid, with the -ic ending changed to -ate Ocurrence: the flavor and fragrance of many fruits and flowers Hydrogen bond acceptor: Volatile than carboxylic acids Cyclic ester: Lactone

How to Prepare Ester ?? - Fischer Esterification - Refluxing a carboxylic acid in an alcohol, which acts as both solvent and reactant Since the reaction is an equilibrium, how to push the equilibrium to the right ???? le Chatelier’s principle !!!

How to Push the equilibrium to the right ? - Fischer Esterification - Using the alcohol as a solvent (in large excess) Using Sulfuric Acid: It acts as an acid catalyst and as a dehydrating agent Distillation (boiling point)

What happens to Fischer Esterification ? Nucleophilic Acyl Substitution !!! Please take a look at eq. 10.19 on page 301 Protecting group Tetrahedral intermediate

Reactions of Esters Saponification, Reduction, Ammonolysis, and Reaction with Grignard Reagent