Ch. 8 - Elimination ReactionsSee all chapters
All Chapters
Ch. 1 - A Review of General Chemistry
Ch. 2 - Molecular Representations
Ch. 3 - Acids and Bases
Ch. 4 - Alkanes and Cycloalkanes
Ch. 5 - Chirality
Ch. 6 - Thermodynamics and Kinetics
Ch. 7 - Substitution Reactions
Ch. 8 - Elimination Reactions
Ch. 9 - Alkenes and Alkynes
Ch. 10 - Addition Reactions
Ch. 11 - Radical Reactions
Ch. 12 - Alcohols, Ethers, Epoxides and Thiols
Ch. 13 - Alcohols and Carbonyl Compounds
Ch. 14 - Synthetic Techniques
Ch. 15 - Analytical Techniques: IR, NMR, Mass Spect
Ch. 16 - Conjugated Systems
Ch. 17 - Aromaticity
Ch. 18 - Reactions of Aromatics: EAS and Beyond
Ch. 19 - Aldehydes and Ketones: Nucleophilic Addition
Ch. 20 - Carboxylic Acid Derivatives: NAS
Ch. 21 - Enolate Chemistry: Reactions at the Alpha-Carbon
Ch. 22 - Condensation Chemistry
Ch. 23 - Amines
Ch. 24 - Carbohydrates
Ch. 25 - Phenols
Ch. 26 - Amino Acids, Peptides, and Proteins

Time to test yourself on what we've learned thus far. You are on your own here. We will be predicting mechanisms so keep the flowchart handy. Good luck! 

Concept #1: Intro to Substitution/Elimination Problems

Time for some practice questions. Have a game plan ready and take it step by step. I believe in you all! Let's begin.

Good job! Way to stick with it. 

Additional Problems
Consider the reaction of each of the following with 1-bromopentane. Which one would have the highest elimination/substitution ratio? a) NaOCH2CH3, ethanol, 55°C b) NaSH, ethanol-water, 25°C  c) KOC(CH3)3, (CH3)3COH, 55°C d) KCN, DMSO, 40°C
Draw the major product(s) for the following reaction in the box provided. Indicate stereochemistry where appropriate. When a racemic mixture is formed, you must draw both enantiomers and write RACEMIC. The mechanism of each reaction (SN2, E2, SN1, or E1) is written below the reaction arrow. Therefore draw your product accordingly.
Predict the product(s) of the following reaction. If no reaction would occur, say so. Show stereochemistry where relevant.
Predict the product; if no reaction occurs, write N.R. If the major product is a mixture of stereoisomers (such as a pair of enantiomers or a pair of diastereomers), give a structural formula for each of the stereoisomers in the mixture. Be sure to show stereoisomers properly when necessary.
For the reaction shown below, draw the structure of the major product(s). Where appropriate, write "No Reaction". Assume all chiral starting materials are optically pure. Show stereochemistry where appropriate. Indicate whether the product exists as a single enantiomer or a racemic mixture.
What is the organic product of the following reaction?  
Predict the organic product of the following reaction. When appropriate, be sure to indicate stereochemistry. If more than one product is formed be sure to indicate the major product. Draw all answers in skeletal form.
Draw a curved arrow mechanism for the following reaction. (Hint: Silver strongly complexes to iodine, allowing it to be more readily abstracted). What type of mechanism is involved in this reaction?
Answer the following questions in reference to the reaction energy diagrams below. The labeled points on the reaction energy diagrams are either energies or chemical species, depending on the sentence.
Provide the mechanism for the following reaction. Be sure to include all intermediates, formal charges and arrows depicting electron movement.
Which one of the following would undergo E2 elimination most rapidly? a. I b. II c. III d. IV e. They would all react at the same rate
Predict the product of the following reaction:  
Provide a reasonable mechanism to account for the following transformations:
Show how you might use a nucleophilic substitution reaction of 1-bromopropane to synthesize each of the following compounds. (You may use any other compounds that are necessary.)  
Show how you might use a nucleophilic substitution reaction of 1-bromopropane to synthesize each of the following compounds. (You may use any other compounds that are necessary.) (b) 1-Iodopropane  
For the following reactions, write the predominant product(s) in the space provided, then in the box above the arrow write the predominant mechanism of the reaction. Make sure to indicate stereochemistry with wedges and dashes as appropriate.
Show how you might use a nucleophilic substitution reaction of 1-bromopropane to synthesize each of the following compounds. (You may use any other compounds that are necessary.)  
With methyl, ethyl, or cyclopentyl halides as your organic starting materials and using any needed solvents or inorganic reagents, outline syntheses of each of the following. More than one step may be necessary and you need not repeat steps carried out in earlier parts of this problem. (a) CH3I  
With methyl, ethyl, or cyclopentyl halides as your organic starting materials and using any needed solvents or inorganic reagents, outline syntheses of each of the following. More than one step may be necessary and you need not repeat steps carried out in earlier parts of this problem.  
Give the best reagent(s) for the following reactions to occur (in the box). Include solvents if applicable. Indicate the reaction type (ex. SN2) on the line next to the product. Indicate the reaction type (ex. SN2/E2/SN1/E1) on the line next to the product box.
With methyl, ethyl, or cyclopentyl halides as your organic starting materials and using any needed solvents or inorganic reagents, outline syntheses of each of the following. More than one step may be necessary and you need not repeat steps carried out in earlier parts of this problem. (c) CH3OH  
With methyl, ethyl, or cyclopentyl halides as your organic starting materials and using any needed solvents or inorganic reagents, outline syntheses of each of the following. More than one step may be necessary and you need not repeat steps carried out in earlier parts of this problem.  
Circle the only compound that cannot undergo an elimination reaction:
With methyl, ethyl, or cyclopentyl halides as your organic starting materials and using any needed solvents or inorganic reagents, outline syntheses of each of the following. More than one step may be necessary and you need not repeat steps carried out in earlier parts of this problem.  
For the reaction below, draw the structure of the missing starting materials, reagents, or final major organic product(s) in the box(es) provided. Make sure to include all the pertinent information about stereochemistry and charges.
Your task is to prepare styrene by one of the following reactions. Which reaction would you choose to give the better yield of styrene? Explain your answer.  
Predict the product of the reaction: 
Determine the mechanism and predict the product of the reaction:  
Determine the mechanism and predict the product of the reaction:  
Determine the mechanism and predict the product of the reaction:  
Determine the mechanism and predict the product of the reaction:  
Determine the mechanism and predict the product of the reaction:
Determine the mechanism and predict the product of the reaction:  
Determine the mechanism and predict the product of the reaction:  
Propose a mechanism that accounts for the formation of all the products shown. If the mechanism has more than one step, show each step separately. Show all charges and keep count of the electrons by the appropriate notation ("curved arrow" or "fishhook" notation).
Fill in the missing reagents:  
Determine the mechanism and predict the product of the reaction:  
Determine the mechanism and predict the product of the reaction:  
Determine the mechanism and predict the product of the reaction:  
Determine the mechanism and predict the product of the reaction:
Determine the mechanism and predict the product of the reaction:  
What is the product of the following elimination? Label the product stereocenter.
Draw the major product of the following reaction.
Specify the mechanisms by which the following pairs of compounds will most likely react.  
What is (are) the most likely product(s) for the following reaction?
Write conformational structures for the substitution products of the following deuterium-labeled compounds:  
Write conformational structures for the substitution products of the following deuterium-labeled compounds:  
Add the missing structures for starting materials, reagents, or products. If asked for the product, just draw the substitution product. You do not need to provide the leaving group. Don’t forget to indicate stereochemistry where appropriate. NO FISHER PROJECTIONS!
Predict the major product
Identify the major product(s) in the reaction of (R)-2-bromopentane with sodium cyanide in DMSO? a) (R)-2-cyanopentane b) (S)-2-cyanopentane c) racemic mixture of 2-cyanopentane d) trans-2-pentene
Give all possible product/products and designate stereoselectivity &/or regioselectivity by using wedges and dashes.   
The reaction between 2-methyl-2-pentanol and HBr to yield 2-methyl-2-pentene is probably: A) an SN1-type reaction involving the protonated alcohol as the substrate. B) an SN2-type reaction involving the protonated alcohol as the substrate. C) an E1-type reaction involving the protonated alcohol as the substrate. D) an E2-type reaction involving the protonated alcohol as the substrate. E) an epoxidation reaction.
Draw the structure, showing the stereochemistry, of the products E and F.
(a) Consider the general problem of converting a tertiary alkyl halide to an alkene, for example, the conversion of tert-butyl chloride to 2-methylpropene. What experimental conditions would you choose to ensure that elimination is favored over substitution?  
Predict the major product
(b) Consider the opposite problem, that of carrying out a substitution reaction on a tertiary alkyl halide. Use as your example the conversion of tert-butyl chloride to tert-butyl ethyl ether. What experimental conditions would you employ to ensure the highest possible yield of the ether?  
Draw the major organic product you expect from each of the following reactions
Draw the major organic productyou expect from the following reaction
Give all possible product/products and designate stereoselectivity &/or regioselectivity by using wedges and dashes.   
Considering the SN1, SN2, E1 and E2 mechanisms, the energy diagram shown below corresponds to a) only the SN1 mechanism. b) only the SN2 mechanism c) both the SN1 and E1 mechanism d) both the SN2 and E2 mechanism
Predict the organic product(s) of the following reaction. When appropriate, be sure to indicate stereochemistry. If more than one product is formed be sure to indicate the major product, if stereoisomers are produced in the reaction be sure to indicate the relationship between them. Draw the answer in skeletal form.
Complete the table below:
Predict the major product
In the solvolysis of  t-butyl chloride, a minor product is 2-methylpropene, which results from the: (CH3)3CCl   +   H2O →  (CH3)3COH  +  (CH3)2C=CH2     major                 minor a) E2 mechanism with OH ¯ acting as the base. b) E2 mechanism with H2O acting as the base. c) E1 mechanism with OH ¯ acting as the base. d) E1 mechanism with H2O acting as the base.
Which is the major product of the following reaction?
True/False. Identify each statements as either True of False. The SN2 reaction of (S)-2-chlorobutane with sodium azide gives a racemic product mixture. In SN1 reactions, the rate determining step is attack of the nucleop`hile. Reactions that have bridged intermediates usually have carbocation rearrangement. Hydrogenation in the presence of Lindlar’s catalyst results in a trans double bond. Fish hook arrows represent single electron transfer. SN1 and E1 reactions have at least 2 transition states in their reaction coordinates. I – (Iodide) is a better nucleophile than F – (Fluoride) in polar protic solvents. 
Supply the reagents needed to perform the following transformation:
Write a chemical equation for the reaction of 1-butanol with each of the following: (b) Hydrogen bromide, heat 
Predict the product for the reaction below.
Each of the following reactions has been described in the chemical literature and involves an organic starting material somewhat more complex than those we have encountered so far. Nevertheless, on the basis of the topics covered in this chapter, you should be able to write the structure of the principal organic product of each reaction. 
Each of the following reactions has been described in the chemical literature and involves an organic starting material somewhat more complex than those we have encountered so far. Nevertheless, on the basis of the topics covered in this chapter, you should be able to write the structure of the principal organic product of each reaction. 
Assuming that the rate-determining step in the reaction of 1-hexanol with hydrogen bromide to give 1-bromohexane is an attack by a nucleophile on an alkyloxonium ion, write an equation for this step. Use curved arrows to show the flow of electrons. 
Write structural formulas for all the alkene products that could reasonably be formed from each of the following compounds under the indicated reaction conditions. Where more than one alkene is produced, specify the one that is the major product. (a) 1-Bromo-3,3-dimethylbutane (potassium tert-butoxide, tert-butyl alcohol, 100°C)  
The following reaction sequence gives rise to two isomeric products A and B. Write the structures of A and B and propose a detailed mechanism for their formation.b. Which one of compounds A and B will be favored under kinetic or thermodynamic control. Explain your answer with one sentence for each compound.    
Write structural formulas for all the alkene products that could reasonably be formed from each of the following compounds under the indicated reaction conditions. Where more than one alkene is produced, specify the one that is the major product. (e) 3-Iodo-2,4-dimethylpentane (sodium ethoxide, ethanol, 70°C)  
For the reaction below, draw the structure of the missing starting materials, reagents, or final major organic product(s) in the box(es) provided. Make sure to include all the pertinent information about stereochemistry and charges.
Complete the two structures of the products according to the mechanism indicated above the arrow. Circle E1 or SN1 above the arrows to indicate the dominant mechanism.
Your task is to prepare isopropyl methyl ether by one of the following reactions. Which reaction would give the better yield? Explain your answer. 
Predict the product(s). 
Predict the major product of the reaction shown.
What would be the operating mechanism in the following reactions ( Sn1, Sn2, E1 or E2 ):
What would be the operating mechanism in the following reactions ( Sn1, Sn2, E1 or E2 ):
Which of the following are the elimination products of the reaction shown below?CH3CH2Br + –OH → ?A) CH3CH2Br+H + OB) CH2 = CH2 + Br – + H2OC) CH2 = CHBr + H2OD) CH3CH2OH + Br –E) HOCH2CH2Br
Show the appropriate arrow-pushing on the left side of the equation, and show the result after the first immediate step on the right side of the equation. (re-write the reagent where necessary!)
Identify the mechanistic pathways, respectively, for the products in the following reaction. A) E1, SN1 B) E1, SN2 C) E2, SN1 D) E2, SN2
Give the major organic product(s) for the following reaction.  
Give the major organic product(s) for the following reaction