Organic Reducing Agents

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Organic Chemistry › Organic Reducing Agents

Questions 1 - 10
1

3-bromopropene was treated with

What is the final major product?

Hexene

6-bromohex-4-ene

Cyclohexene

Hexanol

Explanation

Any time we have a Grignard reagent and a primary haloalkane, we will see a substitution reaction, identical to an reaction. In this case, the Grignard can easily attack the haloalkane as the bromine leaves to create hexene.

2

3-bromopropene was treated with

What is the final major product?

Hexene

6-bromohex-4-ene

Cyclohexene

Hexanol

Explanation

Any time we have a Grignard reagent and a primary haloalkane, we will see a substitution reaction, identical to an reaction. In this case, the Grignard can easily attack the haloalkane as the bromine leaves to create hexene.

3

What is the product of the given reaction?

Screen shot 2015 11 13 at 3.38.24 pm

Screen shot 2015 11 13 at 3.39.24 pm

IV

I

II

III

V

Explanation

First step: esterification

Second step: lithium aluminum hydride reduction

Third step: neutralization to form primary alcohol

Fourth step: SN2 reaction to form final chlorinated product

4

What type of reaction would ensue if the ketone compound shown was introduced to (a Grignard reagent in water).

No reaction

Grignard addition reaction

Oxidation-reduction reaction

Explanation

Grignard reagents are known for their ability to readily attack carbonyls at the point of their carbons. However, Grignard reagents do not work in the presence of protic solvents. Rather than reacting with the desired molecule, the Grignard is so unstable that it will readily accept a proton from a protic solvent. The Grignard then becomes inert and no reaction ensues with the desired molecule.

5

Img 0711

What reactant(s) is/are needed to drive this reaction?

Explanation

The carbons on the epoxide compound experience a slightly positive charge. As a result, a Gringard reagent can easily attack the less substituted side of the epoxide to break the ring and to form a six membered carbon chain. is used to protonate the negatively charged oxygen atom.

Img 0712

6

What type of reaction would ensue if the ketone compound shown was introduced to (a Grignard reagent in water).

No reaction

Grignard addition reaction

Oxidation-reduction reaction

Explanation

Grignard reagents are known for their ability to readily attack carbonyls at the point of their carbons. However, Grignard reagents do not work in the presence of protic solvents. Rather than reacting with the desired molecule, the Grignard is so unstable that it will readily accept a proton from a protic solvent. The Grignard then becomes inert and no reaction ensues with the desired molecule.

7

What is the product of the given reaction?

Screen shot 2015 11 13 at 3.38.24 pm

Screen shot 2015 11 13 at 3.39.24 pm

IV

I

II

III

V

Explanation

First step: esterification

Second step: lithium aluminum hydride reduction

Third step: neutralization to form primary alcohol

Fourth step: SN2 reaction to form final chlorinated product

8

Img 0711

What reactant(s) is/are needed to drive this reaction?

Explanation

The carbons on the epoxide compound experience a slightly positive charge. As a result, a Gringard reagent can easily attack the less substituted side of the epoxide to break the ring and to form a six membered carbon chain. is used to protonate the negatively charged oxygen atom.

Img 0712

9

Which of the following can be reduced when mixed with ?

Explanation

is a very powerful reducing agent that works to reduce almost any carbonyl compound. is an amide and the only carbonyl compound given of the answer choices.

10

Img 0637

What reagents are needed to satisfy the given reaction?

Explanation

Img 0639

This problem requires that we convert our ketone group into a chlorine. However, this cannot be done directly, and requires multiple steps.

We begin by reducing the ketone with to form an alcoxide. The alcoxide undergoes workup (the process whereby a negatively charged oxygen gains a proton) via , depicted above as simply "". We now have a secondary alcohol. From here, we can simply use the reagent to convert the alcohol into the desired chlorine.

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