University:
York University
Course:
CHEM 2021 | Introductory Organic Chemistry II
Academic year:

2023
Views:

339

Pages:

2
Author:

Niklas

5/10 Carboxylic Acid & Acid Deriv. RXN GOES FORWARD → (Nuc. Acyl Subst.) Most Reactive → Least Reactive Acid halide → Acidic anhydride → Ester → Carboxylic acid → Amides → Nitriles TWO TYPES of RXNS: How good is LG? Add'n → Ketones & Aldehydes X = Cl, Br, or I (Bad LG!) reaction mechanism for nucleophilic addition to a carbonyl group How good is C=O? Add'n-Elim. (2 steps) → AKA "Nuc. Acyl Subst." X = Cl, -O-R, OH, -OR, -NH₂ (Good LG!) reaction mechanism for nucleophilic acyl substitution Acid Chlorides (→ FROM Carboxylic Acids) cyclohexane ring with a carboxylic acid group being converted to an acid chloride using SOCl₂, PCl₃, or PCl₅ Mechanism: detailed reaction mechanism showing the nucleophilic acyl substitution reaction between a carboxylic acid and thionyl chloride (SOCl₂) The mechanism involves the following steps: Nucleophilic attack: The lone pair of electrons on the oxygen of the carboxylic acid attacks the sulfur atom of SOCl₂, forming a tetrahedral intermediate. Leaving group departure: The chloride ion leaves as a leaving group, forming a chlorosulfite intermediate. Proton transfer: A proton is transferred from the oxygen to the chlorine, forming HCl. Elimination of SO₂: The sulfur dioxide molecule is eliminated, leaving behind the acid chloride.