Ch. 13 - Alcohols, Ethers and Related Compounds: Substitution and Elimination

Mullins - Organic Chemistry: A Learner Centered Approach 1st Edition

Mullins1st EditionOrganic Chemistry: A Learner Centered ApproachISBN: 9780137566471Not the one you use?Change textbook

Mullins 1st Edition

Ch. 13 - Alcohols, Ethers and Related Compounds: Substitution and Elimination

Problem 106o(iii,iv)

Chapter 12, Problem 106o(iii,iv)

Predict the product(s) that would result when molecules (a)–(p) are allowed to react under the following conditions: (iii) SOCl₂ , NEt₃ (iv) 1. TsCl, Et₃N 2. NaCN; If no reaction occurs, write 'no reaction.'
(o)

Verified step by step guidance

Identify the functional group in the given molecule. The molecule shown is a secondary alcohol, specifically a benzylic alcohol due to the presence of the benzene ring.

For condition (iii) with SOCl₂ and NEt₃: Recognize that SOCl₂ (thionyl chloride) is used to convert alcohols into alkyl chlorides. The reaction proceeds via an S_N2 mechanism, which inverts the configuration at the chiral center.

Predict the product for condition (iii): The hydroxyl group (OH) will be replaced by a chlorine atom (Cl), resulting in the formation of a benzylic chloride with inversion of stereochemistry.

For condition (iv) with 1. TsCl, Et₃N 2. NaCN: Understand that TsCl (tosyl chloride) in the presence of a base like Et₃N converts the alcohol into a tosylate, which is a good leaving group. This is followed by nucleophilic substitution with NaCN.

Predict the product for condition (iv): The hydroxyl group is first converted to a tosylate, and then the tosylate is displaced by the cyanide ion (CN⁻) from NaCN, resulting in the formation of a benzylic nitrile with retention of configuration.

Verified video answer for a similar problem:

This video solution was recommended by our tutors as helpful for the problem above.

Was this helpful?

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Thionyl Chloride (SOCl₂) Reactivity

Thionyl chloride is a reagent commonly used for converting alcohols into alkyl chlorides. It reacts with alcohols to form the corresponding alkyl chloride and byproducts of sulfur dioxide and hydrochloric acid. Understanding this reaction mechanism is crucial for predicting the products when alcohols are treated with SOCl₂ in the presence of a base like NEt₃, which helps to neutralize the generated HCl.

TsCl and Base Reaction

TsCl, or tosyl chloride, is used to convert alcohols into better leaving groups by forming tosylates. When combined with a base like Et₃N, it facilitates the substitution reaction where the tosylate can be further reacted with nucleophiles, such as NaCN. This process is essential for understanding how to predict the products of reactions involving alcohols and nucleophiles after tosylation.

Nucleophilic Substitution Mechanisms

Nucleophilic substitution is a fundamental reaction in organic chemistry where a nucleophile replaces a leaving group in a molecule. There are two main mechanisms: SN1, which involves a carbocation intermediate, and SN2, which is a concerted reaction. Recognizing the conditions and structure of the reactants helps in determining which mechanism will dominate and thus predicting the final products of the reactions described.

Recommended video:

Guided course

01:47

Nucleophiles and Electrophiles can react in Substitution Reactions.

Related Practice

Textbook Question

Predict the product(s) that would result when molecules (a)–(p) are allowed to react under the following conditions: (v) 1. TsCl, Et₃N 2. NaOt-Bu (vi) H₂SO₄ If no reaction occurs, write 'no reaction.'

(o)

views

Textbook Question

Predict the product(s) that would result when molecules (a)–(p) are allowed to react under the following conditions: (ix) PCC; (x) H₂CrO₄ , H₂O. If no reaction occurs, write 'no reaction.'

(o)

views

Textbook Question

Predict the product(s) that would result when molecules (a)–(p) are allowed to react under the following conditions: (ix) PCC; (x) H₂CrO₄ , H₂O If no reaction occurs, write 'no reaction.'

(k)

views

Textbook Question

Predict the product(s) that would result when molecules (a)–(p) are allowed to react under the following conditions: (xi) HOCl, H₂O (xii) HIO₄ If no reaction occurs, write 'no reaction.'

(o)

views

Textbook Question

Predict the product(s) that would result when molecules (a)–(p) are allowed to react under the following conditions: (i) SOCl₂ ; (ii) PBr₃ ; (iii) SOCl₂ , NEt₃ (iv) 1. TsCl, Et₃N 2. NaCN; (v) 1. TsCl, Et₃N 2. NaOt-Bu (vi) H₂SO₄ (vii) HCl; (viii) HBr; (ix) PCC; (x) H₂CrO₄ , H₂O (xi) HOCl, H₂O (xii) HIO₄ If no reaction occurs, write 'no reaction.'

(o)

views

Textbook Question

Predict the product(s) that would result when molecules (a)–(p) are allowed to react under the following conditions: (vii) HCl; (viii) HBr; If no reaction occurs, write 'no reaction.'

(o)

views

Predict the product(s) that would result when molecules (a)–(p) are allowed to react under the following conditions: (iii) SOCl₂ , NEt₃ (iv) 1. TsCl, Et₃N 2. NaCN; If no reaction occurs, write 'no reaction.'(o)

Verified video answer for a similar problem:

Key Concepts

Thionyl Chloride (SOCl₂) Reactivity

TsCl and Base Reaction

Nucleophilic Substitution Mechanisms

Predict the product(s) that would result when molecules (a)–(p) are allowed to react under the following conditions: (iii) SOCl₂ , NEt₃ (iv) 1. TsCl, Et₃N 2. NaCN; If no reaction occurs, write 'no reaction.'
(o)