Organic Chemistry - Reaction Mechanisms - Addition, Elimination, Substitution, & Rearrangement

Organic Chemistry Reactions Study Guide

Addition Reactions: Involves the addition of atoms or groups to a double or triple bond.
- Example: Hydrogenation of alkenes.
Elimination Reactions: Atoms or groups are removed, often forming a double or triple bond.
- Example: Dehydration of alcohols.
Substitution Reactions: An atom or group in a molecule is replaced by another atom or group.
- Example: Halogenation of alkanes.
Redox Reactions: Involves the transfer of electrons, leading to changes in oxidation states.
- Example: Oxidation of alcohols to ketones or aldehydes.

Nucleophiles: Chemicals that donate an electron pair, participate in nucleophilic substitution and addition reactions.
Electrophiles: Chemicals that accept electrons; often involved in addition reactions.
Catalysts: Substances that increase the rate of reaction without being consumed.

Markovnikov's Rule: In addition reactions, the more stable carbocation forms preferentially, leading to the more substituted product.
Anti-Markovnikov Addition: Occurs with the presence of certain reagents such as peroxides in the addition of HBr to alkenes, leading to less substituted products.
SN1 and SN2 Mechanisms:
- SN1: Two-step reaction, involves formation of a carbocation.
- SN2: One-step mechanism, involves direct interaction of nucleophile and electrophile.

Esterification: Formation of esters from carboxylic acids and alcohols.
Grignard Reactions: Reactions involving Grignard reagents to form alcohols.
Aldol Condensation: Forms β-hydroxy aldehydes or ketones via nucleophilic addition of aldehyde with alpha-hydrogen.