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CONCEPT: ALDEHYDE NOMENCLATURE Replace the suffix of the alkane -e with the suffix On the parent chain, the carbonyl is always terminal, and receive a location As substituents, they receive the name and receive a location EXAMPLE: Correctly name the following aldehyde. EXAMPLE: Correctly name the following aldehyde. Page 2
CONCEPT: KETONE NOMENCLATURE Replace the suffix of the alkane -e with the suffix Ketones have higher priority than most groups in Orgo 1, including alcohols When assigning common names to ketones, name both R-groups alphabetically, ending with EXAMPLE: Correctly name the following ketone. 1. EXAMPLE: Correctly name the following ketone. 2. Page 3
CONCEPT: INTRO TO REDOX Oxidation reactions involve an increase in the content of a molecule Reduction reactions involve an increase in the content of a molecule EXAMPLE: Label the following transformations as oxidation or reduction. a. b. c. Page 4
CONCEPT: OXIDATION Oxidizing agents are used to oxidize molecules Most oxidizing agents add as much oxygen as possible while not breaking ANY C-C bonds. EXAMPLE: Which of the following compounds could be oxidized? These are called strong oxidizing agents. They include KMnO4 and the Cr 6+ reagents (H2Cr2O4, CrO3, K2Cr2O7, etc.) EXAMPLE: Draw the products of the previous molecules with a strong oxidizing agent PCC is a weak oxidizing agent. It reacts similar but can only add equivalent of oxygen to 1º alcohols. Page 5
PRACTICE: Provide the major product for the following oxidation reaction. CH 3 OH CH 3 PCC H 3 C OH OH CH 2 Cl 2 PRACTICE: Provide the major product for the following oxidation reaction. H 2 C CH 3 1. O 3 2. Zn, CH 3 CO 2 H PRACTICE: Provide the major product for the following oxidation reaction. OH HO OH KMnO 4 H + PRACTICE: Provide the major product for the following oxidation reaction. Page 6
PRACTICE: Determine the major product for the following reaction. PRACTICE: Determine the major product for the following reaction. PRACTICE: Provide the necessary reagents for the following transformation. Page 7
CONCEPT: WEAK OXIDATIVE CLEAVAGE Ozonolysis: Ketones + Aldehydes + Formaldehyde PRACTICE: Predict the products of the following reaction Page 8
CONCEPT: ALDEHYDES VIA REDUCING AGENTS All of the reducing agents we have learned so far are so powerful that they yield alcohols. We need to use milder reducing agents to yield aldehydes. 1. Typical strong reduction of carbonyls is accomplished via the use of 2. We can reduce the power of the reducing agent by making it sterically hindered: 3. There is another reagent we can use to only induce one equivalent of hydrogen to a carbonyl: Page 9
CONCEPT: ALKYNE HYDRATION Vinyl alcohols are uniquely reactive due to a phenomenon called tautomerization. They reversibly swap the positions of a and a bond. Oxymercuration of Alkynes Product: Hydroboration of Alkynes Product: Page 10
CONCEPT: NUCLEOPHILIC ADDITION One of the most important ways that carbonyl compounds react is through nucleophilic addition. The carbonyl carbon is Nucleophilic Addition General Mechanism: Nucleophilic Addition General Reactions: Page 11
CONCEPT: CYANOHYDRINS Cyanide Addition: Cyanohydrins Cyanohydrin Hydrolysis: Cyanohydrin Reduction: Page 12
PRACTICE: Provide the major product for the following reaction. Page 13
CONCEPT: ORGANOMETALLICS 1. Nucleophilic Addition on Ketones and Aldehydes EXAMPLE: Show the mechanism and predict the product for the following reaction. Page 14
PRACTICE: Provide the major product for the following reaction. Page 15
PRACTICE: Provide the major product for the following reaction dealing with the Grignard reagent. O Mg H 3 O + Br Ether (ROR) Page 16
PRACTICE: Provide the major product for the following reaction dealing with the Grignard reagent. Page 17
PRACTICE: Provide the major product for the following reaction dealing with the Grignard reagent. Br O TMS-Cl Mg OH N(Et) 3 A Ether (ROR) B H 3 O + C Page 18
CONCEPT: NUCLEOPHILIC ADDITION OF SOLVENTS These are reactions that are induced primarily by the extraordinary reactivity at the carbonyl carbon The carbonyl carbon is so reactive that it even reacts with some Most of these mechanisms are acid-catalyzed all are fully reversible in mild acid (H3O + ). Protonation is always the first step, deprotonation is always the last (restores the catalyst) Page 19
CONCEPT: HYDRATES Carbonyl + Water In carbonyls with large R groups, the equilibrium is greatly shifted to the EXAMPLE: Show the mechanism and predict the equilibrium for the following reaction. Page 20
CONCEPT: HEMIACETALS Technically, an is the product of alcohol and aldehyde, while is alcohol and ketone. We will simply use the word acetal to represent these gem-diether structures in general Hemiacetals are only stable when they are. Carbonyl + 1 Eq. Alcohol Acid-Catalyzed Hemiacetal Formation Base-Catalyzed Hemiacetal Formation Page 21
CONCEPT: ACETALS Acetals are stable in and are easily hydrolyzed back to carbonyls using Cyclic acetals are formed by reacting carbonyls with a Carbonyl + 2 Eq. Alcohol Acid-Catalyzed Hemiacetal Formation Acid-Catalyzed Acetal Formation Page 22
PRACTICE: Provide the chemical steps necessary for the following synthesis. O? O O Page 23
PRACTICE: Provide the chemical steps necessary for the following synthesis. Page 24
PRACTICE: Determine the starting materials based on the acetal group present. O O Page 25
CONCEPT: ACETALS AS PROTECTING GROUPS There is a huge difference in reactivity between a carbonyl and an acetal. Which do you think is more reactive? Acetals are used to protect sensitive aldehydes and ketones from reaction with other reagents, since they are reversible. EXAMPLE: Propose a reagent to perform the following transformation. More than one reagent may be required. Page 26
PRACTICE: Provide the chemical steps necessary for the following synthesis. Page 27
PRACTICE: Provide the chemical steps necessary for the following synthesis. O N? O O H H CH 3 Page 28
CONCEPT: THIOACETALS AND RANEY NICKEL REDUCTION Via an almost identical mechanism, thiols can react with aldehydes and ketones to produce thioacetals The Raney nickel catalyst is a convenient way to carbonyls altogether EXAMPLE: Predict the products of the following reaction Page 29
CONCEPT: IMINES AND ENAMINES Primary Amine Addition: Imines Secondary Amine Addition: Enamines All products produce iminium cation, where the deprotonation step will depend on type of amine used. Imine Mechanism: Enamine Mechanism: Page 30
CONCEPT: ADDITION OF AMMONIA DERIVATIVES EXAMPLE: Predict the products of the following reaction. Page 31
CONCEPT: WOLFF-KISCHNER REDUCTION This reaction sequence is used to completely remove carbonyls from alkane chains, much like: a. b. Mechanism: Page 32
CONCEPT: KETONES FROM ACID CHLORIDES When a good leaving group is present on a carbonyl, organometallics tend to react twice, yielding disubstituted alcohols. Nucleophilic Acyl Substitution on Esters and Acid Chlorides From Acid Chlorides: We can reduce the power of the organometal by using a Gilman to yield from RCOCl This reagent stops after the first nucleophilic addition Page 33
PRACTICE: Provide the major product for the following reaction. O Cl (CH 3 CH 2 ) 2 CuLi Ether Page 34
CONCEPT: KETONES FROM NITRILES Nitriles can act very much like carbonyl compounds when exposed to a strong Nu - like a Grignard Mechanism: Page 35
CONCEPT: THE WITTIG REACTION The Wittig forms new carbon-carbon bonds between carbonyl and reactive intermediate called an ylide to yield regiospecific Formation of the Ylide: STEP 1 Alkyl Halide + Triphenylphosphine STEP 2 Deprotonation with a Strong Base STEP 3 Form Oxaphosphetane (mechanism) or Box-Out Method (product). Page 36
PRACTICE: Determine the carbonyl and ylide that formed the following product. Page 37
PRACTICE: Provide the major product for the following reaction. Page 38
PRACTICE: Provide the major product for the following reaction. Page 39
PRACTICE: Provide the chemical steps necessary for the following synthesis. Page 40
PRACTICE: Provide the major product for the following reaction dealing with the Grignard reagent. Page 41