Characteristic Reactions of Functional Groups

Functional Group Reactions

Functional groups are atoms or small groups of atoms (two to four) that exhibit a characteristic reactivity when treated with certain reagents. A particular functional group will almost always display its characteristic chemical behavior when it is present in a compound. Because of this, the discussion of organic reactions is often organized according to functional groups. The following table summarizes the general chemical behavior of the common functional groups. The alkanes are relatively unreactive, and provide a background of behavior in the absence of more localized functional groups.

Functional ClassFormulaCharacteristic Reactions
AlkanesC–C,   C–HCombustion
Substitution (of H by halogen)
  Practice Problems
AlkenesC=CElectrophilic Additions
Strong Brønsted Acids
Lewis Acids (non-Proton Electrophiles)
          Electrophilic Halogen Reagents
          Other Electrophilic Reagents
Radical Additions
Allylic Substitution
  Practice Problems
Addition Reactions
Diels-Alder Cycloaddition
  Practice Problems
AlkynesC≡C–H Addition Reactions
Hydration & Tautomerism
Nucleophilile Addition & Reduction
Acidity of Terminal Alkynes (Substitution of H)
  Practice Problems
Alkyl HalidesH–C–C–XGeneral Reactivity
Substitution(of X)
SN2 Mechanism
SN1 Mechanism
Elimination (of HX)
Summary of Substiution vs. Elimination
Substitution by Metals
Elimination Reactions of Dihalides
  Practice Problems
Reactions of Alcohols
Substitution of the Hydroxyl H
Substitution of the Hydroxyl Group
Elimination of Water (HOH)
Oxidation of Alcohols
Reactions of Phenols
Acidity of Phenols
Ring Substitution of Phenols
Oxidation to Quinones
  Practice Problems
Preparation of Ethers
Reactions of Ethers
Acid Cleavage
Peroxide Formation
Epoxide Reactions
  Practice Problems
Thiols & SulfidesR–S–R'Sulfur Analogs of Alcohols & Ethers
Benzene RingC6H6 Electrophilic Substitution
A Substitution Mechanism
Reactions of Substituted Benzenes
Reaction Characteristics
Reactions of Disubstituted Rings
Reactions of Substituent Groups
Nucleophilic Substitution, Elimination & Addition Reactions
  Practice Problems
AminesC–NRHNomenclature & Structure
Properties of Amines
Boiling Point & Solubility
Basicity of Nitrogen Compounds
Acidity of Nitrogen Compounds
Important Reagent Bases
Reactions of Amines
Electrophilic Substitution at Nitrogen
Preparation of 1º-Amines
Preparation of 2º & 3º-Amines
  Practice Problems
Reactions with Nitrous Acid
Reactions of Aryl Diazonium Intermediates
Elimination Reactions of Amines
Oxidation States of Nitrogen
  Practice Problems
PhosphinesR3PPhosphorus Analogs of Amines
Aldehydes & Ketones(α)C–C=ONomenclature of Aldehydes & Ketones
Occurrence of Aldehydes & Ketones
Natural Products
Synthetic Preparation
Properties of Aldehydes & Ketones
Reversible Addition Reactions
Hydration & Hemiacetal Formation
Acetal Formation
Imine Formation
Enamine Formation
Cyanohydrin Formation
Irreversible Addition Reactions
Complex Metal Hydrides
Organometallic Reagents
Carbonyl Group Modification
Wolff-Kishner Reduction
Clemmensen Reduction
Hydrogenolysis of Thioacetals
Reactions at the α-Carbon
Mechanism of Electrophilic α-Substitution
The Aldol Reaction
Ambident Enolate Anions
Alkylation of Enolate Anions
  Practice Problems
Carboxylic Acids(α)C–CO2H Nomenclature of Carboxylic Acids
Natural Products
Related Derivatives
Physical Properties
Preparation of Carboxylic Acids
Reactions of Carboxylic Acids
Salt Formation
Substitution of Hydroxyl Hydrogen
Substitution of the Hydroxyl Group
Reduction & Oxidation
  Practice Problems
Carboxylic Derivatives
(Z = OR, Cl, NHR, etc.)
Physical Properties
Reactions of Carboxylic Acid Derivatives
Acyl Group Substitution
 Catalytic Reduction
 Metal Hydride Reduction
 Diborane Reduction
Reaction with Organometallic Reagents
Reactions at the α Carbon
Acidity of α C–H
The Claisen Condensation
Synthesis Applications
  Practice Problems

Special or Advanced Topics

At various points throughout this text, links to supplementary information or special topics will be located in shaded boxes of this kind.

Concerning Practice Problems

The practice problems provided as part of this text are chiefly interactive, and should provide a useful assessment of the reader's understanding at various stages in the development of the subject. Some of these problems make use of a Molecular Editor drawing application created by Peter.Ertl of the Novartis Corp. To practice using this editor Click Here.
Since problem solving is essential to achieving an effective mastery of the subject, it is recommended that many more problems be worked. Most organic chemistry textbooks contain a broad assortment of suitable problems, and paperback collections of practice problems are also available.
The button on the right will activate a collection of problems concerning the reactivity of common functional groups.

The following web-sites provide nice collections of problems and answers:

Reaction quizzes and summaries from Towson University
Electronic flashcards from Ohio State University
Concept questions from University of Wisconsin
Practice problems from UCLA
Spectroscopy problems from Notre Dame

For a useful collection of study materials, including links to other sites, visit the Organic chemistry tool-kit. Prepared by Bob Hanson, St. Olaf College

These pages are the property of William Reusch.
1999 William Reusch, All rights reserved
(most recent revision 5/1/2004)
Comments, questions and errors should be sent to

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