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CHEM104: Organic Chemistry II

Unit 6: Aldehydes & Ketones   Aldehydes and ketones are the first compounds we have seen in this course that contain the carbonyl functional group.  This group entails a carbon-oxygen double bond, or C=O.  If the carbon atom is bound to at least one hydrogen atom, it is an aldehyde.  If C is bound to two other carbons, then it is a ketone.  Aldehydes and ketones react mostly via nucleophilic addition, where a nucleophile attacks the electron-poor carbon of the carbonyl group.

Unit 6 Time Advisory
This unit will take you 13 hours to complete.

☐    Subunit 6.1: 2 hours

☐    Subunit 6.2: 0.75 hours

☐    Subunit 6.3: 8.25 hours

☐    Readings: 3 hours

☐    Lecture: 0.25 hours

☐    Web Media: 4.5 hours

☐    Assignments: 0.5 hour

☐    Subunit 6.4: 2 hours

Unit6 Learning Outcomes
Upon successful completion of this unit, the student will be able to: - Derive the name of aldehydes and ketones from their molecular structure, and vice versa. - Describe the physical properties of aldehydes and ketones. - Describe common reactions used to prepare aldehydes and ketones. - Describe the mechanism, reagents involved, and reaction conditions for the reversible and irreversible addition of nucleophiles. - Choose the proper oxidizing and/or reducing agents to synthesize a desired product.

6.1 Nomenclature, Structural, and Physical Properties   - Web Media: YouTube: Freelanceteach’s “Naming Aldehydes, Ketones, and Carboxylic Acids (1)” Link: YouTube: Freelanceteach’s “Naming Aldehydes, Ketones, and Carboxylic Acids (1)” (YouTube)

 Instructions: Please click on the link above, and watch this video
(\#1) in its entirety (9:30 minutes) to start learning about the
nomenclature of aldehydes and ketones.   
    
 Viewing this lecture and pausing to take notes should take
approximately 15 minutes to complete.  

 Terms of Use: Please respect the copyright and terms of use
displayed on the webpage above. 
  • Web Media: YouTube: Freelanceteach’s “Naming Aldehydes, Ketones, and Carboxylic Acids (2);” “Naming Aldehydes, Ketones, and Carboxylic Acids (3);” and “Naming Aldehydes, Ketones, and Carboxylic Acids (4)” Links: YouTube: Freelanceteach’s “Naming Aldehydes, Ketones, and Carboxylic Acids (2);” (YouTube)  “Naming Aldehydes, Ketones, and Carboxylic Acids (3);” (YouTube) and “Naming Aldehydes, Ketones, and Carboxylic Acids (4)” (YouTube)
     
    Instructions: Please note that these video lectures are optional.  For an in-depth explanation of the properties of aldehydes and ketones, you may choose to click on the links above and watch lectures 2-4.  These lectures run at approximately 4 minutes, 11 minutes, and 2 minutes respectively.  This material is not required for successful completion of the course.   

    Viewing these optional lectures should take approximately 30 minutes to complete.

    Terms of Use: Please respect the copyright and terms of use displayed on the webpages above.

  • Reading: Michigan State University: Professor William Reusch’s Virtual Textbook of Organic Chemistry: “Aldehydes and Ketones” Link: Michigan State University: Professor William Reusch’s Virtual Textbook of Organic Chemistry: “Aldehydes and Ketones” (HTML)
     
    Instructions: In the chapter “Aldehydes and Ketones” linked above, read sections 1, 2, and 4. Skip 3: “Synthetic Preparation of Aldehydes and Ketones.”  Aldehydes and ketones are characterized by the carbonyl functional group, C=O.  Because carbon can accommodate four bonds, there are two bonds available for a hydrogen or an alkyl group.  Aldehydes have at least one hydrogen bonded to the carbonyl carbon while ketones have no hydrogens but rather two alkyl groups. 

    This reading should take approximately 1 hour to complete.
     
    Terms of Use: Please respect the copyright and terms of use displayed on the webpage above.  

  • Lecture: Khan Academy’s “Aldehyde Introduction” and “Ketone Naming” Link: Khan Academy’s “Aldehyde Introduction” (YouTube) and “Ketone Naming” (YouTube)

    Instructions: Please click on the links above, and watch the two video lectures to reinforce the material covered in the reading. 

    Viewing these lectures should take approximately 20 minutes to complete.

    Terms of Use: These videos are licensed under a Creative Commons Attribution-NonCommercial-NoDerives United States License 3.0.  They are attributed to the Khan Academy. 

6.2 Synthesis of Aldehydes and Ketones   - Reading: Michigan State University: Professor William Reusch’s Virtual Textbook of Organic Chemistry: “Synthetic Preparation of Aldehydes and Ketones” Link: Michigan State University: Professor William Reusch’s Virtual Textbook of Organic Chemistry:Synthetic Preparation of Aldehydes and Ketones” (HTML)

 Instructions: Please click on the link above, and read this section
about synthesis of aldehydes and ketones.  The most common reactions
for the preparation of aldehydes and ketones have been previously
covered earlier in this course.  A few examples are through the
oxidation of primary and secondary alcohols, and hydration of
alkynes. These and other reactions for preparing aldehydes and
ketones will be covered in this section.  

 This reading should take approximately 30 minutes to complete.  

 Terms of Use: Please respect the copyright and terms of use
displayed on the webpage above. 
  • Lecture: Khan Academy’s “Friedel Crafts Acylation” and “Friedel Crafts Acylation Addendum” Link: Khan Academy’s “Friedel Crafts Acylation” (YouTube) and “Friedel Crafts Acylation Addendum” (YouTube)

    Instructions: Please click on the links above, and watch the two video lectures to reinforce the material covered in the reading.  Friedel Crafts acylation is an application of electrophilic aromatic substitution of benzene, which was covered sub-sub-unit 4.3.1.   

    Viewing these lectures and pausing to take notes should take approximately 15-20 minutes to complete.

    Terms of Use: These videos are licensed under a Creative Commons Attribution-NonCommercial-NoDerives United States License 3.0.  They are attributed to the Khan Academy. 

6.3 Reactions of Aldehydes and Ketones   6.3.1 Nucleophilic Addition to the Carbonyl Carbon   - Reading: Michigan State University: Professor William Reusch’s Virtual Textbook of Organic Chemistry: “Reactions of Aldehydes and Ketones” and "Aldehydes and Ketones II: Reactions at the Alpha Carbon" Links: Michigan State University: Professor William Reusch’s Virtual Textbook of Organic Chemistry:Reactions of Aldehydes and Ketones” (HTML) and "Aldehydes and Ketones II: Reactions at the Alpha Carbon" (HTML)

 Instructions: Please click on the links above, and read these
sections about reactivity of aldehydes and ketones in their
entirety.  Note that an important feature of aldehydes and ketones
chemistry is that the carbonyl carbon reacts readily to incoming
carbon nucleophiles (partial negative carbons).  As a result,
reactions of aldehydes and ketones are a useful means to lengthen
the carbon chain to produce more complex organic molecules.
 Aldehydes and ketones will also easily undergo substitution
reactions at an alpha carbon.  You will learn about these reactions
in this section as well as a mechanism for the nucleophilic addition
reaction.  This resource covers subunits 6.3.1-6.3.6.  

 Reading and taking notes should take approximately 3 hours to
complete.  

 Terms of Use: Please respect the copyright and terms of use
displayed on the webpages above.  

6.3.2 Reversible Addition Reactions   Note: This subunit is covered by the resources assigned beneath subunit 6.3.1.  Reversible reactions of the carbonyl group result in the formation of hemiacetal, acetals, imines, enamine, and cyanohydrins.  Refer to Professor Reusch’s “Reactions of Aldehydes and Ketones:” “Reversible Addition Reactions” to learn about these reactions.

6.3.3 Irreversible Addition Reactions   Note: This subunit is covered by the resources assigned beneath subunit 6.3.1.  These reaction types of the carbonyl group go by reduction by complex metal hydrides and the addition of organometallic (Grignard) reagents.  The partial negative charge of the hydride or organometallic reagent attacks the partially positive carbonyl carbon.  Refer to Professor Reusch’s “Reactions of Aldehydes and Ketones:” “Irreversible Addition Reactions” to learn about these reactions.

6.3.4 Reduction and Oxidation Reactions   Note: This subunit is covered by the resources assigned beneath subunit 6.3.1.  Reactions involving reduction at the carbonyl carbon include the Wolff-Kishner Reduction, Clemmensen Reduction, and Hydrogenolysis of Thioacetals.  Refer to Professor Reusch’s “Reactions of Aldehydes and Ketones:” “Other Carbonyl Group Reactions” to learn about reduction and oxidation of aldehydes and ketones at the carbonyl.

6.3.5 Reactions at the ?-Carbon   Note: This subunit is covered by the resources assigned beneath subunit 6.3.1.  Reactions at the alpha carbon of aldehydes and ketones occur via electrophilic substitution. Refer to Professor Reusch’s “Aldehydes & Ketones II:” “Reactions at the Alpha Carbon” to learn about the mechanism of electrophilic alpha substitution and the Aldo condensation reaction.

  • Lecture: Khan Academy’s “Keto Enol Tautomerization” Link: Khan Academy’s “Keto Enol Tautomerization”(YouTube)

    Instructions: Please click on the link above, and watch the video lecture to learn about a specific type of electrophilic alpha-substitution called keto-enol tautomerization.  Keto-enol tautomerization describes the equilibrium that exists between a ketone (or aldehyde) and an alcohol.  This concept will be revisited in subunit 9.1, when aldol reactions are introduced. 

    Viewing this lecture and pausing to take notes should take approximately 15 minutes to complete.

    Terms of Use: These videos are licensed under a Creative Commons Attribution-NonCommercial-NoDerives United States License 3.0.  They are attributed to the Khan Academy. 

6.3.6 Irreversible Substitution Reactions   Note: This subunit is covered by the resources assigned beneath subunit 6.3.1.  Irreversible substitution reactions of aldehydes and ketones are important in the synthesis of organic compounds.  This topic is covered under Professor Reusch’s “Aldehydes & Ketones II:”  “Irreversible Substitution Reactions” to learn about enolate anions and alkylation.

6.4 Problems Involving Aldehydes and Ketones   - Web Media: YouTube: Freelanceteach’s “Aldehyde and Ketone Problems” Lectures 1-12 Link: YouTube: Freelanceteach’s “Aldehyde and Ketone Problems” Lectures 1-12 (YouTube)
Aldehyde and Ketone Problems (1)
Aldehyde and Ketone Problems (2)
Aldehyde and Ketone Problems (3)
Aldehyde and Ketone Problems (4)
Aldehyde and Ketone Problems (5)
Aldehyde and Ketone Problems (6)
Aldehyde and Ketone Problems (7)
Aldehyde and Ketone Problems (8)
Aldehyde and Ketone Problems (9)
Aldehyde and Ketone Problems (10)
Aldehyde and Ketone Problems (11)
Aldehyde and Ketone Problems (12)

 Instructions:  Please click on the links above, and watch the
entire series of videos (\#1-12), in which the lecturer solves and
explains aldehyde and ketone problems.  These videos range in run
time from 4-11 minutes.  This resource covers the topics in subunits
6.1-6.4.  
    
 Viewing these lectures should take approximately 2 hours to
complete.  
    
 Terms of Use: Please respect the copyright and terms of use
displayed on the webpages above.