Download Chapter 13: Aldehydes and Ketones - Structure, Reactions, and Nomenclature - Prof. Cheng-W and more Exams Organic Chemistry in PDF only on Docsity! 1 Chapter 13. Aldehydes and Ketones Learning objectives: 1. Provide both IUPAC and common names for aldehydes and ketones. 2. Recognize the physical properties of for aldehydes and ketones. 3. Write the general electron-pushing (arrow-pushing) mechanisms for the nucleophilic addition to a carbonyl group with the following nucleophiles: Grignard reagent, alcohol, water, and amine. 4. Write the general electron-pushing (arrow-pushing) mechanism for the tautomerization between keto and enol, and explain the observed racemization at the α-carbon. 5. Recognize the reagents for the transformation from aldehyde to carboxylic acid. 6. Recognize the reagents and conditions used for the reduction of aldehyde and ketone to alcohol. 7. Utilize reductive amination for the synthesis of amines. 8. Recognize the reagents and conditions used for α-halogenation. Sections to be covered (in the order of delivery): 13.1 Introduction # 13.2 Structure and Bonding 13.3 Nomenclature 13.4 Physical Properties 13.5 Reactions * 13.6 Addition of Grignard Reagents * 13.7 Addition of Alcohols * 13.8 Addition of Ammonia and Amines * 13.9 Keto-Enol Tautomerism * 13.10 Oxidation 13.11 Reduction * Sections that will be focused # Sections that will be skipped Recommended additional problems 13.12 – 13.30, 13.33, 13.35 – 13.39, 13.43 2 13.2 Structure and Bonding H H O R H O R R' O 13.3 Nomenclature O H O H O H O H H H O O O H O H HO H OCH2CH3 O O OCH2CH3 CHO O Cl 5 13.6 Addition of Grignard Reagents A. Formation and Structure of Organomagnesium Compounds B. Reaction with Protic Acids C. Addition of Grignard Reagents to Aldehydes and Ketones 6 13.7 Addition of Alcohols A. Formation of Acetals and Ketals with Water R H (R) O R H(R) HO OH H2O (i) Consideration of pKa (ii) Stability consideration 7 B. Addition of Alcohol: Formation of Hemiacetal, Acetal, Hemiketal, and Ketal) R H O R H R'O OR' HOR' R H R'O OH (2 equivalents) H2O R R O R R R'O OR' HOR' R R R'O OH (2 equivalents) H2O C. Mechanism 10 B. Reductive Amination of Aldehydes and Ketones 13.9 Keto-Enol Tautomerism A. Keto and Enol Forms R CH2R' O R CHR' OH 11 B. Racemization at an α-Carbon C H C H3C CH3 O (R)-3-Phenyl-2-butanone Mechanism and Consequence of tautomerization: 12 C. α-Halogenation CH3 O X2 (Cl2, Br2, I2) H3O + CH2 O X 13.10 Oxidation A. Oxidation of Aldehydes to Carboxylix Acids (i) Examples O O H2CrO4 H2CrO4 (ii) Tollens’ Reagent (Silver-mirror Test) AgNO3 + 2 NH3 Ag(NH3)2 + NO3 - H O + 2 Ag(NH3)2 + O - O + +2 Ag 4 NH3
