
What sequence of reactions would best accomplish the following reaction?

A. (i) $LiAl{{H}_{4}}$ in ether; (ii) ${{P}_{2}}{{O}_{5}}$ and heat.
B. (i) $LiAl{{H}_{4}}$ in ether; (ii) $3C{{H}_{3}}I$ followed by heating with AgOH.
C. (i) $20%{{H}_{2}}S{{O}_{4}}$ and heat; (ii) ${{P}_{2}}{{O}_{5}}$ and heat.
D. ${{H}_{2}}$ and Lindlar catalyst.
Answer
162.6k+ views
Hint: Alkyl cyanide can not be converted into alkene by a single step, more than one step is involved. Therefore different reagents are used in this regard. One simple method to solve this problem is to apply the different reagents given in the option, only then we can reach that particular pathway.
Complete step by step solution:
Putting the reagents in the given alkyl cyanide one by one:
(i) Alkyl cyanide compound forms alkyl amine with $LiAl{{H}_{4}}$in ether and presence of ${{P}_{2}}{{O}_{5}}$ heat, alkenes are not formed.
(ii) Here also alkyl amine is formed at the first step. Under the presence of $C{{H}_{3}}I$ AgOH Hoffmann elimination reaction occurs. It is the process of forming tertiary amine and alkenes from the treatment of quaternary ammonium ions with excess $C{{H}_{3}}I$ followed by treating silver oxide, water, and heat. If the alkyl groups contain beta hydrogens, then elimination occurs. Finally, we get the desired product.

(iii) Under the condition $20%{{H}_{2}}S{{O}_{4}}$and heat a carboxylic acid is formed followed by decarboxylation with the removal of carbon dioxide in the next step.

(iv) ${{H}_{2}}$and Lindlar catalyst can reduce only internal alkyne into cis alkenes but not reduce alkyl cyanide. Therefore, option B is a suitable pathway to synthesize the given alkene.
Thus, option (B) is correct.
Note: To approach this type of synthesis reaction, one should remember some important reagents and name reactions that will help to guess the product without any broad mechanism. Also, the basic idea of general organic chemistry is mandatory such as inductive effect, acidity, basicity hyperconjugation, resonance, electrophiles, and nucleophiles.
Complete step by step solution:
Putting the reagents in the given alkyl cyanide one by one:
(i) Alkyl cyanide compound forms alkyl amine with $LiAl{{H}_{4}}$in ether and presence of ${{P}_{2}}{{O}_{5}}$ heat, alkenes are not formed.
(ii) Here also alkyl amine is formed at the first step. Under the presence of $C{{H}_{3}}I$ AgOH Hoffmann elimination reaction occurs. It is the process of forming tertiary amine and alkenes from the treatment of quaternary ammonium ions with excess $C{{H}_{3}}I$ followed by treating silver oxide, water, and heat. If the alkyl groups contain beta hydrogens, then elimination occurs. Finally, we get the desired product.

(iii) Under the condition $20%{{H}_{2}}S{{O}_{4}}$and heat a carboxylic acid is formed followed by decarboxylation with the removal of carbon dioxide in the next step.

(iv) ${{H}_{2}}$and Lindlar catalyst can reduce only internal alkyne into cis alkenes but not reduce alkyl cyanide. Therefore, option B is a suitable pathway to synthesize the given alkene.
Thus, option (B) is correct.
Note: To approach this type of synthesis reaction, one should remember some important reagents and name reactions that will help to guess the product without any broad mechanism. Also, the basic idea of general organic chemistry is mandatory such as inductive effect, acidity, basicity hyperconjugation, resonance, electrophiles, and nucleophiles.
Recently Updated Pages
Two pi and half sigma bonds are present in A N2 + B class 11 chemistry JEE_Main

Which of the following is most stable A Sn2+ B Ge2+ class 11 chemistry JEE_Main

The enolic form of acetone contains a 10sigma bonds class 11 chemistry JEE_Main

The specific heat of metal is 067 Jg Its equivalent class 11 chemistry JEE_Main

The increasing order of a specific charge to mass ratio class 11 chemistry JEE_Main

Which one of the following is used for making shoe class 11 chemistry JEE_Main

Trending doubts
JEE Main 2025 Session 2: Application Form (Out), Exam Dates (Released), Eligibility, & More

JEE Main 2025: Derivation of Equation of Trajectory in Physics

Displacement-Time Graph and Velocity-Time Graph for JEE

Types of Solutions

Degree of Dissociation and Its Formula With Solved Example for JEE

Electric Field Due to Uniformly Charged Ring for JEE Main 2025 - Formula and Derivation

Other Pages
JEE Advanced Marks vs Ranks 2025: Understanding Category-wise Qualifying Marks and Previous Year Cut-offs

JEE Advanced Weightage 2025 Chapter-Wise for Physics, Maths and Chemistry

NCERT Solutions for Class 11 Chemistry In Hindi Chapter 1 Some Basic Concepts of Chemistry

NCERT Solutions for Class 11 Chemistry Chapter 7 Redox Reaction

JEE Advanced 2025: Dates, Registration, Syllabus, Eligibility Criteria and More

Verb Forms Guide: V1, V2, V3, V4, V5 Explained
