a) Interpretation: The product formed and the electron pushing mechanism for its formation, when 2-pentyne is reduced with Li in NH 3 is to be given. Concept introduction: Lithium metal donates an electron to the alkyne to give an anion radical which in the next step abstracts a proton from ammonia solvent to yield a vinylic radical. In the third step the vinylic radical accepts a second electron from another Li atom to produce a vinylic anion which in the fourth step abstracts another proton from ammonia solvent to yield the final trans product. The addition takes place with trans stereochemistry. The stereochemistry is established in the third step when the less hindered vinylic anion is formed from vinylic radical. To propose: The product formed and the electron pushing mechanism for its formation, when 2-pentyne is reduced with Li in NH 3 .

Question

Show the mechanism and give the products for the following reaction. Pay attention to regio/stereo-chemistry.

Answer 1

Question

Chapter 9.SE, Problem 22MP

Interpretation Introduction

a)

Interpretation:

The product formed and the electron pushing mechanism for its formation, when 2-pentyne is reduced with Li in NH₃ is to be given.

Concept introduction:

Lithium metal donates an electron to the alkyne to give an anion radical which in the next step abstracts a proton from ammonia solvent to yield a vinylic radical. In the third step the vinylic radical accepts a second electron from another Li atom to produce a vinylic anion which in the fourth step abstracts another proton from ammonia solvent to yield the final trans product.

The addition takes place with trans stereochemistry. The stereochemistry is established in the third step when the less hindered vinylic anion is formed from vinylic radical.

To propose:

The product formed and the electron pushing mechanism for its formation, when 2-pentyne is reduced with Li in NH₃.

Interpretation Introduction

b)

Interpretation:

The product formed and the electron pushing mechanism for its formation, when 3-methyl-1-butyne is reduced with Li in ND₃ is to be given.

Concept introduction:

Lithium metal donates an electron to the alkyne to give an anion radical which in the next step abstracts a proton from deuteratedammonia solvent to yield a vinylic radical. In the third step the vinylic radical accepts a second electron from another Li atom to produce a vinylic anion which in the fourth step abstracts another proton from the solvent to yield the final trans product.

The addition takes place with trans stereochemistry. The stereochemistry is established in the third step when the less hindered vinylic anion is formed from vinylic radical.

To propose:

The product formed and the electron pushing mechanism for its formation, when 3-methyl-1-butyne is reduced with Li in ND₃.

Interpretation Introduction

c)

Interpretation:

The product formed and the electron pushing mechanism for its formation, when propynylbenzene is reduced with Li in NH₃ is to be given.

Concept introduction:

Lithium metal donates an electron to the alkyne to give an anion radical which in the next step abstracts a proton from ammonia solvent to yield a vinylic radical. In the third step the vinylic radical accepts a second electron from another Li atom to produce a vinylic anion which in the fourth step abstracts another proton from ammonia solvent to yield the final trans product.

The addition takes place with trans stereochemistry. The stereochemistry is established in the third step when the less hindered vinylic anion is formed from vinylic radical.

To propose:

The product formed and the electron pushing mechanism for its formation, when propynylbenzene is reduced with Li in NH₃.

Expert Solution & Answer

Trending nowThis is a popular solution!

See solution

Check out sample textbook solution

Students have asked these similar questions

Show the mechanism and give the products for the following reaction. Pay attention to regio/stereo-chemistry.

Predict the major products of the following reactions. Please show mechanisms in detail.

An elimination step is involved in the synthesis of aromatic amino acids. We can also envision this occurring in a laboratory setting with a strong base. Provide a 1 step mechanism for this decarboxylation reaction. Note: under strongly basic conditions, hydroxide is a reasonable leavinggroup.

Answer 2

Question

Chapter 9.SE, Problem 22MP

Interpretation Introduction

a)

Interpretation:

The product formed and the electron pushing mechanism for its formation, when 2-pentyne is reduced with Li in NH₃ is to be given.

Concept introduction:

Lithium metal donates an electron to the alkyne to give an anion radical which in the next step abstracts a proton from ammonia solvent to yield a vinylic radical. In the third step the vinylic radical accepts a second electron from another Li atom to produce a vinylic anion which in the fourth step abstracts another proton from ammonia solvent to yield the final trans product.

The addition takes place with trans stereochemistry. The stereochemistry is established in the third step when the less hindered vinylic anion is formed from vinylic radical.

To propose:

The product formed and the electron pushing mechanism for its formation, when 2-pentyne is reduced with Li in NH₃.

Interpretation Introduction

b)

Interpretation:

The product formed and the electron pushing mechanism for its formation, when 3-methyl-1-butyne is reduced with Li in ND₃ is to be given.

Concept introduction:

Lithium metal donates an electron to the alkyne to give an anion radical which in the next step abstracts a proton from deuteratedammonia solvent to yield a vinylic radical. In the third step the vinylic radical accepts a second electron from another Li atom to produce a vinylic anion which in the fourth step abstracts another proton from the solvent to yield the final trans product.

The addition takes place with trans stereochemistry. The stereochemistry is established in the third step when the less hindered vinylic anion is formed from vinylic radical.

To propose:

The product formed and the electron pushing mechanism for its formation, when 3-methyl-1-butyne is reduced with Li in ND₃.

Interpretation Introduction

c)

Interpretation:

The product formed and the electron pushing mechanism for its formation, when propynylbenzene is reduced with Li in NH₃ is to be given.

Concept introduction:

Lithium metal donates an electron to the alkyne to give an anion radical which in the next step abstracts a proton from ammonia solvent to yield a vinylic radical. In the third step the vinylic radical accepts a second electron from another Li atom to produce a vinylic anion which in the fourth step abstracts another proton from ammonia solvent to yield the final trans product.

The addition takes place with trans stereochemistry. The stereochemistry is established in the third step when the less hindered vinylic anion is formed from vinylic radical.

To propose:

The product formed and the electron pushing mechanism for its formation, when propynylbenzene is reduced with Li in NH₃.

Expert Solution & Answer

Trending nowThis is a popular solution!

See solution

Check out sample textbook solution

Answer 3

Question

Chapter 9.SE, Problem 22MP

Interpretation Introduction

a)

Interpretation:

The product formed and the electron pushing mechanism for its formation, when 2-pentyne is reduced with Li in NH₃ is to be given.

Concept introduction:

Lithium metal donates an electron to the alkyne to give an anion radical which in the next step abstracts a proton from ammonia solvent to yield a vinylic radical. In the third step the vinylic radical accepts a second electron from another Li atom to produce a vinylic anion which in the fourth step abstracts another proton from ammonia solvent to yield the final trans product.

The addition takes place with trans stereochemistry. The stereochemistry is established in the third step when the less hindered vinylic anion is formed from vinylic radical.

To propose:

The product formed and the electron pushing mechanism for its formation, when 2-pentyne is reduced with Li in NH₃.

Interpretation Introduction

b)

Interpretation:

The product formed and the electron pushing mechanism for its formation, when 3-methyl-1-butyne is reduced with Li in ND₃ is to be given.

Concept introduction:

Lithium metal donates an electron to the alkyne to give an anion radical which in the next step abstracts a proton from deuteratedammonia solvent to yield a vinylic radical. In the third step the vinylic radical accepts a second electron from another Li atom to produce a vinylic anion which in the fourth step abstracts another proton from the solvent to yield the final trans product.

The addition takes place with trans stereochemistry. The stereochemistry is established in the third step when the less hindered vinylic anion is formed from vinylic radical.

To propose:

The product formed and the electron pushing mechanism for its formation, when 3-methyl-1-butyne is reduced with Li in ND₃.

Interpretation Introduction

c)

Interpretation:

The product formed and the electron pushing mechanism for its formation, when propynylbenzene is reduced with Li in NH₃ is to be given.

Concept introduction:

Lithium metal donates an electron to the alkyne to give an anion radical which in the next step abstracts a proton from ammonia solvent to yield a vinylic radical. In the third step the vinylic radical accepts a second electron from another Li atom to produce a vinylic anion which in the fourth step abstracts another proton from ammonia solvent to yield the final trans product.

The addition takes place with trans stereochemistry. The stereochemistry is established in the third step when the less hindered vinylic anion is formed from vinylic radical.

To propose:

The product formed and the electron pushing mechanism for its formation, when propynylbenzene is reduced with Li in NH₃.

Expert Solution & Answer

Trending nowThis is a popular solution!

See solution

Check out sample textbook solution

Answer 4

Question

Chapter 9.SE, Problem 22MP

Interpretation Introduction

a)

Interpretation:

The product formed and the electron pushing mechanism for its formation, when 2-pentyne is reduced with Li in NH₃ is to be given.

Concept introduction:

Lithium metal donates an electron to the alkyne to give an anion radical which in the next step abstracts a proton from ammonia solvent to yield a vinylic radical. In the third step the vinylic radical accepts a second electron from another Li atom to produce a vinylic anion which in the fourth step abstracts another proton from ammonia solvent to yield the final trans product.

The addition takes place with trans stereochemistry. The stereochemistry is established in the third step when the less hindered vinylic anion is formed from vinylic radical.

To propose:

The product formed and the electron pushing mechanism for its formation, when 2-pentyne is reduced with Li in NH₃.

Interpretation Introduction

b)

Interpretation:

The product formed and the electron pushing mechanism for its formation, when 3-methyl-1-butyne is reduced with Li in ND₃ is to be given.

Concept introduction:

Lithium metal donates an electron to the alkyne to give an anion radical which in the next step abstracts a proton from deuteratedammonia solvent to yield a vinylic radical. In the third step the vinylic radical accepts a second electron from another Li atom to produce a vinylic anion which in the fourth step abstracts another proton from the solvent to yield the final trans product.

The addition takes place with trans stereochemistry. The stereochemistry is established in the third step when the less hindered vinylic anion is formed from vinylic radical.

To propose:

The product formed and the electron pushing mechanism for its formation, when 3-methyl-1-butyne is reduced with Li in ND₃.

Interpretation Introduction

c)

Interpretation:

The product formed and the electron pushing mechanism for its formation, when propynylbenzene is reduced with Li in NH₃ is to be given.

Concept introduction:

Lithium metal donates an electron to the alkyne to give an anion radical which in the next step abstracts a proton from ammonia solvent to yield a vinylic radical. In the third step the vinylic radical accepts a second electron from another Li atom to produce a vinylic anion which in the fourth step abstracts another proton from ammonia solvent to yield the final trans product.

The addition takes place with trans stereochemistry. The stereochemistry is established in the third step when the less hindered vinylic anion is formed from vinylic radical.

To propose:

The product formed and the electron pushing mechanism for its formation, when propynylbenzene is reduced with Li in NH₃.

Expert Solution & Answer

Trending nowThis is a popular solution!

See solution

Check out sample textbook solution

Answer 5

Chapter 9.SE, Problem 22MP

Interpretation Introduction

a)

Interpretation:

The product formed and the electron pushing mechanism for its formation, when 2-pentyne is reduced with Li in NH₃ is to be given.

Concept introduction:

Lithium metal donates an electron to the alkyne to give an anion radical which in the next step abstracts a proton from ammonia solvent to yield a vinylic radical. In the third step the vinylic radical accepts a second electron from another Li atom to produce a vinylic anion which in the fourth step abstracts another proton from ammonia solvent to yield the final trans product.

The addition takes place with trans stereochemistry. The stereochemistry is established in the third step when the less hindered vinylic anion is formed from vinylic radical.

To propose:

The product formed and the electron pushing mechanism for its formation, when 2-pentyne is reduced with Li in NH₃.

Interpretation Introduction

b)

Interpretation:

The product formed and the electron pushing mechanism for its formation, when 3-methyl-1-butyne is reduced with Li in ND₃ is to be given.

Concept introduction:

Lithium metal donates an electron to the alkyne to give an anion radical which in the next step abstracts a proton from deuteratedammonia solvent to yield a vinylic radical. In the third step the vinylic radical accepts a second electron from another Li atom to produce a vinylic anion which in the fourth step abstracts another proton from the solvent to yield the final trans product.

The addition takes place with trans stereochemistry. The stereochemistry is established in the third step when the less hindered vinylic anion is formed from vinylic radical.

To propose:

The product formed and the electron pushing mechanism for its formation, when 3-methyl-1-butyne is reduced with Li in ND₃.

Interpretation Introduction

c)

Interpretation:

The product formed and the electron pushing mechanism for its formation, when propynylbenzene is reduced with Li in NH₃ is to be given.

Concept introduction:

Lithium metal donates an electron to the alkyne to give an anion radical which in the next step abstracts a proton from ammonia solvent to yield a vinylic radical. In the third step the vinylic radical accepts a second electron from another Li atom to produce a vinylic anion which in the fourth step abstracts another proton from ammonia solvent to yield the final trans product.

The addition takes place with trans stereochemistry. The stereochemistry is established in the third step when the less hindered vinylic anion is formed from vinylic radical.

To propose:

The product formed and the electron pushing mechanism for its formation, when propynylbenzene is reduced with Li in NH₃.

Answer 6

Chapter 9.SE, Problem 22MP

Interpretation Introduction

a)

Interpretation:

The product formed and the electron pushing mechanism for its formation, when 2-pentyne is reduced with Li in NH₃ is to be given.

Concept introduction:

Lithium metal donates an electron to the alkyne to give an anion radical which in the next step abstracts a proton from ammonia solvent to yield a vinylic radical. In the third step the vinylic radical accepts a second electron from another Li atom to produce a vinylic anion which in the fourth step abstracts another proton from ammonia solvent to yield the final trans product.

The addition takes place with trans stereochemistry. The stereochemistry is established in the third step when the less hindered vinylic anion is formed from vinylic radical.

To propose:

The product formed and the electron pushing mechanism for its formation, when 2-pentyne is reduced with Li in NH₃.

Answer 7

Chapter 9.SE, Problem 22MP

Interpretation Introduction

a)

Interpretation:

The product formed and the electron pushing mechanism for its formation, when 2-pentyne is reduced with Li in NH₃ is to be given.

Concept introduction:

Lithium metal donates an electron to the alkyne to give an anion radical which in the next step abstracts a proton from ammonia solvent to yield a vinylic radical. In the third step the vinylic radical accepts a second electron from another Li atom to produce a vinylic anion which in the fourth step abstracts another proton from ammonia solvent to yield the final trans product.

The addition takes place with trans stereochemistry. The stereochemistry is established in the third step when the less hindered vinylic anion is formed from vinylic radical.

To propose:

The product formed and the electron pushing mechanism for its formation, when 2-pentyne is reduced with Li in NH₃.

Answer 8

Interpretation Introduction

b)

Interpretation:

The product formed and the electron pushing mechanism for its formation, when 3-methyl-1-butyne is reduced with Li in ND₃ is to be given.

Concept introduction:

Lithium metal donates an electron to the alkyne to give an anion radical which in the next step abstracts a proton from deuteratedammonia solvent to yield a vinylic radical. In the third step the vinylic radical accepts a second electron from another Li atom to produce a vinylic anion which in the fourth step abstracts another proton from the solvent to yield the final trans product.

The addition takes place with trans stereochemistry. The stereochemistry is established in the third step when the less hindered vinylic anion is formed from vinylic radical.

To propose:

The product formed and the electron pushing mechanism for its formation, when 3-methyl-1-butyne is reduced with Li in ND₃.

Answer 9

Interpretation Introduction

b)

Interpretation:

The product formed and the electron pushing mechanism for its formation, when 3-methyl-1-butyne is reduced with Li in ND₃ is to be given.

Concept introduction:

Lithium metal donates an electron to the alkyne to give an anion radical which in the next step abstracts a proton from deuteratedammonia solvent to yield a vinylic radical. In the third step the vinylic radical accepts a second electron from another Li atom to produce a vinylic anion which in the fourth step abstracts another proton from the solvent to yield the final trans product.

The addition takes place with trans stereochemistry. The stereochemistry is established in the third step when the less hindered vinylic anion is formed from vinylic radical.

To propose:

The product formed and the electron pushing mechanism for its formation, when 3-methyl-1-butyne is reduced with Li in ND₃.

Answer 10

Interpretation Introduction

c)

Interpretation:

The product formed and the electron pushing mechanism for its formation, when propynylbenzene is reduced with Li in NH₃ is to be given.

Concept introduction:

Lithium metal donates an electron to the alkyne to give an anion radical which in the next step abstracts a proton from ammonia solvent to yield a vinylic radical. In the third step the vinylic radical accepts a second electron from another Li atom to produce a vinylic anion which in the fourth step abstracts another proton from ammonia solvent to yield the final trans product.

The addition takes place with trans stereochemistry. The stereochemistry is established in the third step when the less hindered vinylic anion is formed from vinylic radical.

To propose:

The product formed and the electron pushing mechanism for its formation, when propynylbenzene is reduced with Li in NH₃.

Answer 11

Interpretation Introduction

c)

Interpretation:

The product formed and the electron pushing mechanism for its formation, when propynylbenzene is reduced with Li in NH₃ is to be given.

Concept introduction:

Lithium metal donates an electron to the alkyne to give an anion radical which in the next step abstracts a proton from ammonia solvent to yield a vinylic radical. In the third step the vinylic radical accepts a second electron from another Li atom to produce a vinylic anion which in the fourth step abstracts another proton from ammonia solvent to yield the final trans product.

The addition takes place with trans stereochemistry. The stereochemistry is established in the third step when the less hindered vinylic anion is formed from vinylic radical.

To propose:

The product formed and the electron pushing mechanism for its formation, when propynylbenzene is reduced with Li in NH₃.

Answer 12

Expert Solution & Answer

Answer 13

Expert Solution & Answer

Answer 14

Trending nowThis is a popular solution!

See solution

Check out sample textbook solution

Answer 15

Trending nowThis is a popular solution!

See solution

Check out sample textbook solution

Answer 16

Trending nowThis is a popular solution!

See solution

Check out sample textbook solution

Answer 17

Trending nowThis is a popular solution!

Answer 18

Trending nowThis is a popular solution!

Answer 19

Trending nowThis is a popular solution!

Answer 20

Trending now

Answer 21

This is a popular solution!

Answer 22

See solution

Check out sample textbook solution

Answer 23

Ch. 9.1 - Prob. 1P Ch. 9.1 - Prob. 2P Ch. 9.3 - What products would you expect from the following...Ch. 9.4 - Prob. 4P Ch. 9.4 - Prob. 5P Ch. 9.4 - Prob. 6P Ch. 9.4 - Prob. 7P Ch. 9.5 - Using any alkyne needed, how would you prepare the...Ch. 9.7 - The pKa of acetone, CH3COCH3, is 19.3. Which of...Ch. 9.8 - Prob. 10P

Solution Summary: The author explains that 2-pentyne gets an electron from the lithium metal to give an anion radical which in the next step abstracts a proton from ammonia solvent.

Chapter 9 Solutions