Carboxylic Acid Derivatives: Nucleophilic Acyl Substitution Chapter 19 Carboxylic Acid Derivatives: Nucleophilic Acyl Substitution WWU-Chemistry

Assignment Skip the following sections: 19.1, 19.11, 19.15, 19.16, 19.18, 19.21 and 19.32 These PowerPoint slides have been revised for Fall 2007. Some additional sections have been dropped or minimized! WWU-Chemistry

Problem Assignment In-Text: 1 a, c 4, 5a - d, 6 a - c 8 a, c 9 -11 15 - 19 21 - 23 26, 27 31 - 40 End-of-Chapter: 4 6 - 9 15 WWU-Chemistry

The addition/elimination mechanism WWU-Chemistry

Nucleophilic Acyl Substitution WWU-Chemistry

Sect. 19.2, 19.3 and 19.4 Nomenclature for acid chlorides, acid anhydrides and esters Only ester nomenclature on test! WWU-Chemistry

Acid part of ester Alcohol part of ester WWU-Chemistry

Ethyl ethanoate (IUPAC) Ethyl acetate (common) WWU-Chemistry

Methyl 2-methylpropanoate WWU-Chemistry

Ethyl pentanoate WWU-Chemistry

Methyl cyclohexanecarboxylate WWU-Chemistry

Isopropyl benzoate or 2-methylethyl benzoate WWU-Chemistry

Ethyl 5-bromo-3,4-dimethylhexanoate WWU-Chemistry

Ethyl 5-bromo-3,4-dimethyl-2,4-hexadienoate WWU-Chemistry

Sect. 19.5 and 19.6: Nomenclature for amides and nitriles Skip these sections! Not on test! WWU-Chemistry

Sect. 19.7: Mechanisms Base hydrolysis of an ester WWU-Chemistry

Sect. 19.8/ 19.9: Preparation and reactions of acid chlorides Important!!! Acid chlorides are key intermediates for making esters, amides and anhydrides!!!! WWU-Chemistry

Preparation of an Ester WWU-Chemistry

Preparation of an Amide WWU-Chemistry

Preparation of an Anhydride WWU-Chemistry

Sect. 19.10: Reducing agents Review of reductions on acid chlorides. A look at the reduction of all the derivatives of carboxylic acids. We talked about this in Chapter 16! WWU-Chemistry

Reactions of sodium borohydride Aldehydes yield primary alcohols Ketones yield secondary alcohols Esters give no reaction! Amides give no reaction! WWU-Chemistry

Reactions of lithium aluminum hydride Aldehydes give primary alcohols Ketones give secondary alcohols Esters give primary alcohols from the carboxylic acid part of the ester (Sect 19.20) Amides give primary amines!! (Sect 19.24) WWU-Chemistry

Sect. 19.11: skip WWU-Chemistry

Sect. 19.12: carboxylic acid derivatives Esters Amides Anhydrides Nitriles All of these functional groups will be hydrolyzed in acidic or basic water to give the parent carboxylic acid WWU-Chemistry

Sect. 19.13 and 9.14: Esters WWU-Chemistry

Esters as Flavoring Substances WWU-Chemistry

Fischer Esterification ESTERIFICATION REACTIONS ARE REVERSIBLE. You need to push it to the right (ester) by removing water as it forms. This reaction is acid catalyzed WWU-Chemistry

Fischer esterification is an acid catalyzed reaction WWU-Chemistry

Sect. 19.15 and 19.16 -- skip WWU-Chemistry

Sect. 19.17: Hydrolysis of Esters See slide for section 19.7 for mechanism of base hydrolysis Mechanism of the acid catalyzed hydrolysis reaction is the reverse of the Fischer esterification reaction! WWU-Chemistry

Sect. 19.18: skip WWU-Chemistry

Sect. 19.19: Reaction of Esters with Organometallic Reagents WWU-Chemistry

Mechanism WWU-Chemistry

Sect. 19.20: Reduction of Esters Lithium aluminum hydride gives the primary alcohol WWU-Chemistry

Diisobutylaluminum hydride (DibalH) gives the aldehyde WWU-Chemistry

Sect. 19.21: skip WWU-Chemistry

Sect. 19.22 and 19.23: Preparation and Reactions of Amides Heat WWU-Chemistry

Remember, also prepare amides from acid chlorides WWU-Chemistry

Amides, continued Keep this section simple, skip the DCC stuff WWU-Chemistry

Sect. 19.24: Reduction of amides amides give primary amines with lithium aluminum hydride. WWU-Chemistry

Sect. 19.25 and 19.26: Reactions of anhydrides WWU-Chemistry

Preparation of aspirin and acetaminophen (Tylenol) WWU-Chemistry

Sect. 19.27 and 19.28: preparation and reactions of nitriles WWU-Chemistry

Base-Promoted Hydrolysis of a Nitrile (Part One) WWU-Chemistry

Base-Promoted Hydrolysis of a Nitrile (Part Two) WWU-Chemistry

Sect. 19.29: reduction of nitriles with lithium aluminum hydride and Hydrogen WWU-Chemistry

The remaining sections will not be included on the third test. WWU-Chemistry

Sect. 19.30: Fats and oils (Triglycerides) WWU-Chemistry

The Fatty Acids WWU-Chemistry

Sect. 19.31, 19.33, 19.34 soaps proteins condensation polymers WWU-Chemistry

Wallace Carothers- commercialized Nylon at DuPont Source: Michigan State University, Department of Chemistry http://www.chemistry.msu.edu/Portraits/PortraitsHH_collection.shtml WWU-Chemistry

Functional Group Interconversions H2O OH- R’OH H2O H2O SOCl2 R’OH OH- NH3 NR’2H NH3 NR’2H RCOOH H2O RCOOH NH3 NR’2H NH3 NR’2H WWU-Chemistry