Epoxide Reactions - Online Tutor, Practice Problems & Exam Prep

Draw the product(s) formed from the reaction below.

Write suitable reagents for the given reaction.

Determine the major product for the base-catalyzed ring-opening reaction of 2,2-diethyloxirane with 0.1 M NaOH.

Determine the major product for the base-catalyzed ring-opening reaction of 2,2-diethyloxirane with CH₃O^-/CH₃OH.

What is the mechanism of the given synthesis?

Suggest a plausible mechanism for the base-catalyzed ring-opening of benzene oxide. In your mechanism, use Nu^- as a generic nucleophile.

In determining the major product in the rearrangement of the given arene oxide, NIH shift was established. In this reaction, the hydrogen is replaced by deuterium.

The NIH shift occurs in the reaction; determine the major product.

1,2-epoxycycloheptane is converted into trans-2-methoxycycloheptan-1-ol by treatment with anhydrous HCl in methanol. Propose a mechanism for this reaction.

Propose the mechanism of the acid-catalyzed ring opening of epoxide given below.

Propose the mechanism for the acid-catalyzed ring opening of epoxide given below.

Determine the final products expected in each of the reactions given below.

Show how tetramethylethylene oxide will react when treated with each of the following reagents.

(a) NaOCH₂CH₃ (sodium ethoxide)
(b) NaNH₂ (sodium amide)
(c) NaSPh (sodium thiophenoxide) 

Give the major products expected in each of the reactions given below. Also, show the stereochemistry.

What is the structure of the product that results from the epoxide addition reaction given below?

The product in the ring opening of the epoxide depends on whether it happened under acidic or basic conditions. For the reaction below, the epoxide opens in the same way under either condition; explain why.

What is the product of the reaction below when epoxide reacts with acid and alcohol?

Consider the following acid-catalyzed ring-opening reaction of an epoxide:

Calculate ΔH° based on the bonds formed and broken.

The following synthesis is carried out via a cationic cyclization cascade.

What is its possible reaction mechanism? (Note: The carbons are numbered for you.)

Propose a mechanism for the following reaction. [Hint: The formation of the carbocation will trigger a cyclization.]

Suggest a plausible mechanism for the following reaction. [Hint: A cyclization will occur after the carbocation is formed.]

Consider the addition reaction shown below. Aside from opening the ring, provide another driving force for the reaction.

True or False. The major products of the rearrangements of the arene oxides shown below are identical.

Two arene oxides could be generated from 3a¹,5a¹-dihydropyrene. What are their structures?

What are the structures of the phenols generated from the given arene oxide?

What is the reaction mechanism for the following?

Ethylene oxide reacts readily with OH⁻. Why does cyclopropane, a compound with the same three-membered ring strain, not react with OH⁻?

Draw the products for the reaction of the epoxide, cyclopentene oxide, with ethoxide ion.

Determine which of the given reactions below would be faster.

Deuterium replaces hydrogen to show the existence of the NIH shift by determining the major product obtained through the rearrangement of the given arene oxide.

For the given reaction, draw the major product of the carbocation that would form a phenol by losing either H⁺ or D⁺ rather than undergoing NIH shift.

Determine the products for the reaction of the epoxide, cyclopentene oxide, with ethylamine.

For the given reaction:

(i) The reaction could also form another product, a seven-membered molecule. Draw the structure of the product.

(ii) Explain why so few of the seven-membered ring molecules (the other product) were formed.

Draw the stereoisomers produced from the reaction of the following alkenes with m-CPBA followed by OH⁻, H₂O.

What stereoisomers form from the reaction of the following alkenes with m-CPBA, followed by OH⁻, H₂O?

The following arene oxide rearranges into two phenols. Which phenol will be the major product?

Consider the following compound:

This compound could be produced using propene as the only carbon source. Show how you would accomplish this.

Consider the following:

What is the reaction mechanism for the formation of the cyclized intermediate?

What is/are the correct products for the reactions shown below?

(i) What is the structure for the stereoisomers of 2-isopropyloxirane? (ii) What is the mechanism for the acid-catalyzed hydrolysis of pure (R)- 2-isopropyloxirane?

Predict the major product (including stereochemistry) formed in the following reaction:

trans-hept-3-ene + peroxyacetic acid in water

(i) Suggest a mechanism for the conversion of cis-oct-4-ene to its corresponding epoxide (2,3-dipropyloxirane) followed by the ring-opening reaction to give the glycol, octane-4,5-diol. Account for stereochemistry. [Use a generic acid catalyst and peroxy acid.]

(ii) Do the above for trans-oct-4-ene.

(iii) Compare the products from (i) and (ii). Can the reaction sequence be identified as a stereospecific reaction?

Propose a mechanism for the following acid-catalyzed double cyclization. Hint: The mechanism looks like the cyclization of squalene oxide to lanosterol.

Predict the major products (including stereochemistry if applicable) formed from the following reactions.

(i) (2S,3R)-2,3-diethyl-2-methyloxirane + CH₃CH₂O^–/CH₃CH₂OH

(ii) (2S,3R)-2,3-diethyl-2-methyloxirane + H⁺/CH₃CH₂OH

Propose a mechanism for the following acid-catalyzed cyclization of a substituted oxirane. Ignore stereochemistry.

Ignoring stereochemistry, draw the product formed from the reaction of 2,3-dimethyloxirane with each of the following:

(i) KN₃ (potassium azide)

(ii) C₆H₁₁NH₂ (cyclohexanamine)

(iii) NaCN (sodium cyanide)

Draw the product(s) formed when the given molecule reacts with mCPBA, followed by sulfuric acid.

Draw the product(s) formed when the given alkene undergoes a reaction with (1) m-CPBA and then with (2) H₂SO₄ (aq).

(a) Propose a mechanism for epoxidation and acid-catalyzed ring opening of trans-hex-3-ene.

(b) Predict the final product for the reaction of cis-hex-3-ene under the same conditions.

Provide the mechanisms that produce the two enantiomers in the following reaction.

Draw the arrows to show the mechanism for parts (i)–(iv) in the given sequence.

Draw the product for the reaction of 1-methyl-4-(prop-1-en-2-yl)cyclopent-1-ene and an excess of peroxyacetic acid in acidic water.

Suggest a plausible mechanism for the reaction shown below.

Examine the following reactions and predict the major products. 

Predict the reagents for the following reaction.

Determine the final products expected in each of the reactions given below.

One of the products, when an excess of propylene oxide reacts with hydroxide ion, is tripropylene glycol. Provide a possible mechanism for the given reaction.