Ch. 10 - Addition 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

This reaction adds a 3-membered cyclic ether (epoxide functional group) to an alkene using reagents called peroxy acids. These epoxides are highly strained, so they can react in very useful ring-opening reactions, which we will discuss later. 

Epoxides from Peroxy Acids

Concept #1: General properties of epoxidation.     

Peroxy acids are compounds with the general molecular formula RCO3H. The most common examples are MCPBA and MMPP. These are essentially the same molecule, just with different –R groups. 

Concept #2: The mechanism of how peroxy acids make epoxides.   

You typically won’t need to know this entire mechanism, but here is the first step:

General Reaction:

Note: There should also be a partial bond drawn in where the double bond used to be on the cyclohexane. 

Epoxides from Halohydrins

Concept #3: The mechanism of how halohydrins make epoxides via intramolecular SN2.  

Halohydrins can be deprotonated using a base to become a nucleophilic O-. Once this anion is created, it can participate in an intramolecular SN2 reaction with the halogen next to it, making a three-membered ring closure

Additional Problems
For the reaction below, draw the structure of the appropriate compound. Indicate stereochemistry where it is pertinent.
Through what mechanism can a 1,2-halohydrin be converted into an epoxide? A) electrophilic addition B) E2 C) SN2 D) SN1 E) polymerization
Specify reagents suitable for converting 3-ethyl-2-pentene to each of the following: (f) 2,3-Epoxy-3-ethylpentane 
Draw the structural formula of the major organic product(s) in the box for the following reaction.
All the following reactions have been reported in the chemical literature. Give the structure of the principal organic product in each case.
When trans-2-bromo-cyclohexan-1-ol is reacted with sodium hydroxide in water, an epoxide is formed. When cis-2-bromo-cyclohexan-1-ol is reacted with sodium hydroxide in water, an epoxide is NOT formed. Using complete sentences and Lewis structures, explain why an epoxide is not formed with the cis-compound.
Predict the product of the following reaction:   
Provide a reasonable mechanism to account for the following transformations:
Using line-angle ONLY, draw the MAJOR product expected from the following reaction. Be sure to show stereochemistry if appropriate. If no reaction occurs write NR.
Write the structure of the major organic product formed in the reaction of 2-methyl-2-butene with each of the following: (i) Peroxyacetic acid 
Consider the strucutres below and answer the following questions.  i. Which compound(s) would react with RCO3R and then NaOH to form a meso compound. (An achiral molecule with chirality centers?) 
Predict the organic product(s) of the following reaction. When appropriate, be sure to indicate stereochemistry. Be sure to indicate the major product if more than one product is formed. Draw all answers in skeletal form. 
Predict the product of the following reaction: 
Which reaction(s) would produce the epoxide shown? 1) A only 2) B only 3) A and B 4) B and C 5) All of them will work
Write the structure of the major organic product formed in the reaction of 1-methylcyclohexene with each of the following: (i) Peroxyacetic acid 
Draw the chemical structure for mCPBA.
Williamson ether synthesis of epoxides. a) Draw the structure of products B and D, showing the stereochemistry. b) Circle the product (B or D), which has an [α] D = +98°. c) What kind of isomers are B and D. d) Draw the structure of the isomer of B and D, which has an [α]  D = -98°.
Propose a detailed mechanism for the proposed conversion of A to B. Show the key intermediates and the products obtained after each step.
If cis-2-butene is treated with meta-chloroperbenzoic acid what is the final product? A) I  B) II C) III D) IV E) None of the above
Supply a structural formula for the major organic product ; if no reaction occurs, write N.R. Give the best possible answer. Be sure to show stereoisomers properly when necessary.
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 all answers in skeletal form.
On catalytic hydrogenation over a rhodium catalyst, the compound shown gave a mixture containing cis-1-tert-butyl-4-methylcyclohexane (88%) and trans-1-tert-butyl- 4-methylcyclohexane (12%). With this stereochemical result in mind, consider the reactions in (a) and (b).(a) What two products are formed in the epoxidation of this compound? Which one do you think will predominate?
Show mechanism for following reactions and transformations.
Shown below is one step in the synthesis of racemic trans-2-(1-propenyl)cyclohexanol from cyclohexane. From the list of reagents provided, choose the reagent(s) that will bring about this transformation. a. Br2, light b. HBr c. H2SO4, H2O d. H2C=CH-CH2MgBr HCl/H2O e. (CH3)3CO-K+ f. RCO3H g. CH3OH h. 1. CH3CH=CHMgBr      2. HCl/H2O (No more than one step is necessary. Write the letter of the reagent(s) in the box provided, e.g., g) Your answer:
Draw the organic product of the following reaction.
What is the product of the following reaction?
Predict the oxidation product of treating the given alkone with the reagents shown belw. Only draw one enantiomer if more than one is possible.