Ch. 12 - Alcohols, Ethers, Epoxides and ThiolsSee 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

Alcohols are terrible leaving groups. So we’re going to learn an entire class of reagents whose sole job is to convert alcohol into better leaving groups. 

Concept #1: Why do we need to convert Alcohol into a good leaving group?

We’re aiming to turn alcohols into alkyl halides or sulfonate esters. Let’s explore the different ways to accomplish this. 

The simplest way to theoretically convert alcohols into alkyl halides is just to react them with a strong halohydric acid (HX). There are some complications associated with this conversion however.

 

Can you predict what they are? (Three major complications given below).  

Concept #2: Using HX acids via SN1 reaction.  

This is the predominant mechanism for strong halohydric acids with 2° and 3° alcohols. 

Concept #3: Using HX acids via SN2 reaction.

This is the predominant mechanism for strong halohydric acids with 1° alcohols.

Complications: Strong HX acids conversions come with three major complications.

  1. Regiochemistry of products: Carbocation intermediates can rearrange.
  2. Stereochemistry of products: Racemic products are non-stereo specific.
  3. Competition of Elimination mechanisms: Some product won’t even be an alkyl halide.   

These complications render this method mostly useless. Sorry not sorry.  

Additional Problems
Provide a complete mechanism for the following transformation.
Predict the major product for the following reaction A) I                             B) II                            C) III                          D) IV                          E) V          
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.
The transformation of the hydroxyl group into a good leaving group can be accomplished through the use of various reagents. 
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 your answer in skeletal form. You will be graded on the product your draw from the reaction no other information is needed for this question.
Compound A reacts with HBr via an SN1 process leading to 3 different constitutional isomers. Draw the structure of these products.
Based on the SN1 mechanism for the reaction of tertiary alcohols with HCl as summarized in arrows 1 and 2, which arrow(s) represent(s) more than one elementary step? a. Arrow 1b. Arrow 2c. Both 1 and 2d. Neither 1 nor 2
Provide a step-by-step mechanism for the reaction below. Include all mechanisms, formal charges, and curved arrow pushing of electrons.
Write a chemical equation for the reaction of 1-butanol with each of the following:  (c) Sodium bromide, sulfuric acid, heat
Predict the product:
The following reaction below is probablyA) 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.
SHOW THE MECHANISM(S) of the following reaction(s), by the method indicated:Show by electron pushing the key transition state in the reaction of 4-methyl-1-pentanol with concentrated HI. (Note: You need not show the transition states for any proton transfers.)
Draw the major organic product(s) of the following reaction (multiple products may be drawn in one box):
Draw the major organic product(s) of the following reaction. 
For the following SN1 reaction, draw the major organic product, identify the nucleophile, substrate, and leaving group, and determine the rate limiting step.  
Alcohols can act as either acids or bases, similar to water. In the box below draw the products of the following reaction:
What stereoisomers does the following reaction form?  
Draw the major organic product (s) of the following reaction (multiple products may be drawn in one box):
Draw the major organic produce(s) of the following reaction (multiple products may be drawn in one box).
What is the major product of the following substitution reaction?
Give all the structures of the products you would expect when 2-methylbutan-2-ol reacts with HBr.
Give the structures of the products you would expect when cis-3-methylcyclopentanol reacts with HCl/ZnCl2.
Alcohols can act as either acids or bases, similar to water. In the box below draw the products of the following reaction: 
Predict the product(s) formed when the structure shown below undergoes a reaction with concentrated HBr. If there is more than one product, draw all products possible.
Draw the major organic product(s) of the following reaction (multiple products may be drawn in one box):
Provide the structure of the major organic product in the reaction below. 
Draw the major organic product(s) of the following reaction (multiple products may be drawn in one box):