Ch. 16 - Conjugated SystemsSee all chapters
All Chapters
Ch. 1 - A Review of General Chemistry
Ch. 2 - Molecular Representations
Ch. 3 - Acids and Bases
Ch. 4 - Alkanes and Cycloalkanes
Ch. 5 - Chirality
Ch. 6 - Thermodynamics and Kinetics
Ch. 7 - Substitution Reactions
Ch. 8 - Elimination Reactions
Ch. 9 - Alkenes and Alkynes
Ch. 10 - Addition Reactions
Ch. 11 - Radical Reactions
Ch. 12 - Alcohols, Ethers, Epoxides and Thiols
Ch. 13 - Alcohols and Carbonyl Compounds
Ch. 14 - Synthetic Techniques
Ch. 15 - Analytical Techniques: IR, NMR, Mass Spect
Ch. 16 - Conjugated Systems
Ch. 17 - Aromaticity
Ch. 18 - Reactions of Aromatics: EAS and Beyond
Ch. 19 - Aldehydes and Ketones: Nucleophilic Addition
Ch. 20 - Carboxylic Acid Derivatives: NAS
Ch. 21 - Enolate Chemistry: Reactions at the Alpha-Carbon
Ch. 22 - Condensation Chemistry
Ch. 23 - Amines
Ch. 24 - Carbohydrates
Ch. 25 - Phenols
Ch. 26 - Amino Acids, Peptides, and Proteins

Conjugated Hydrohalogenation (1,2 vs 1,4 addition)

See all sections
Sections
Conjugation Chemistry
Stability of Conjugated Intermediates
Allylic Halogenation
Conjugated Hydrohalogenation (1,2 vs 1,4 addition)
Diels-Alder Reaction
Diels-Alder Forming Bridged Products
Diels-Alder Retrosynthesis
Molecular Orbital Theory
Drawing Atomic Orbitals
Drawing Molecular Orbitals
HOMO LUMO
Orbital Diagram: 3-atoms- Allylic Ions
Orbital Diagram: 4-atoms- 1,3-butadiene
Orbital Diagram: 5-atoms- Allylic Ions
Orbital Diagram: 6-atoms- 1,3,5-hexatriene
Orbital Diagram: Excited States
Pericyclic Reaction
Thermal Cycloaddition Reactions
Photochemical Cycloaddition Reactions
Thermal Electrocyclic Reactions
Photochemical Electrocyclic Reactions
Cumulative Electrocyclic Problems
Sigmatropic Rearrangement
Cope Rearrangement
Claisen Rearrangement
Additional Practice
Conjugated Halogenation
Diels-Alder Inductive Effects
Diels-Alder Regiospecficity
Diels-Alder Asymmetric Induction
Diels-Alder Synthesis
Allylic SN1 and SN2
Cumulative Orbital Diagram Problems
Cumulative Cycloaddition Reactions
Cumulative Sigmatropic Problems
UV-Vis Spect Basics
UV-Vis Spect Beer's Law
Molecular Electronic Transition Therory
Woodward-Fieser Rules
Additional Guides
Diene

Conjugated hydrohalogenation, also known as hydrohalogenation of dienes, or 1,2 vs. 1,4 addition to dienes, is the same reaction as hydrohalogenation, except with a possibility of multiple products due to the presence of a conjugated intermediate. 

Concept #1: Conjugated Hydrohalogenation - General Mechanism

Example #1: 1,2 vs. 1,4 products

Example #2: 1,2 vs. 1,4 products

Concept #2: Kinetic vs. Thermodynamic Control

Additional Problems
Electrophilic addition reaction of conjugated dienes that occur at high temperature and/or long reaction times (reversible conditions) are said to be under: A) 1,2-Control B) 1,4-Control C) Kinetic Control D) Thermodynamic Control E) None of these
Fill in the structure of the missing module of the reaction by paying attention to regio - and stereochemistry where necessary. 
Write a mechanism for the reaction of 2,3-dimethyl-1,3-cyclohexadiene with one equivalent of HBr. Provide structural formulas for the products and label each as "1,2-adduct" or "1,4-adduct.”
A product of thermodynamic control. a) is formed fastest. b) is favored by lower temperature. c) has the lowest energy transition state. d) none of the above.
Using arrows to show the flow of electrons, write a stepwise mechanism for the reaction shown below. Give all important resonance structures for each reactive intermediate. For your mechanism, concisely explain why X = 81% and Y = 19% when the reaction is performed at -80°C and why X = 44% and Y = 56% when the reaction is performed at room temperature (25°C).
Draw the structures of the major products of the following reactions.
Draw the structure of the major product of the following reaction.
Consider the reaction below and answer the following question.  
Answer the following questions using the image below. The nucleophile in this reaction is ____: The electrophile in this reaction is ____: The kinetically controlled product in this reaction is _____: The product that results from 1,4-addition is _____:
What compound results from the 1,4-addition of one equivalent of HBr to 1,3-butadiene a. 2-bromo-2-butene b. 1-bromo-1-butene c. 4-bromo-1-butene d. 1 bromo-2-butene e. 3-bromo-1-butene
Predict the organic product(s) of the following reaction. When appropriate, be sure to indicate stereochemistry. If more than one product is formed be sure to indicate the major product, if stereoisomers are produced in the reaction be sure to indicate the relationship between them. Draw the answer in skeletal form.
Consider the reaction in the box, which is carried out under   thermodynamic  conditions, and circle the most likely product from the choices provided.
a. Predict the product(s) in the following hydrohalogenation. Label the products as either the kinetic or thermodynamic product.  b. Draw the product(s) into the correct position on the energy diagram, and draw a  CIRCLE around the molecule that you believe to be the major product. 
What is the kinetically controlled product in the following reaction?
Fill in the structure of the missing molecule for the following reaction below.
The thermodynamically controlled product in this reaction is ______.
Write the structure(s) of the product(s) for the reaction below. Be sure to indicate any relevant stereochemistry. 
The product that results from 1,4-addition is _____:
Draw the major 1, 2- and 1, 4-addition products that form as a result of the following reaction between one equivalent each of 2, 4-hexadiene and HBr.
Predict the major product of the following reaction  
Draw the two major products obtained in the reaction shown.  
Predict the products of the following reaction.  
Draw the two major products pbtained in the reaction shown.
Draw the two major products obtained in the reaction shown. You do not have to consider stereochemistry. You do not have to explicitly draw H atoms. Draw one structure per sketcher. Add additional sketchers using
Predict the products of the following reactions. 
Give the major organic product for the reaction: 
Draw the two major products obtained in the reaction shown. You do not have to consider stereochemistry. You do not have to explicitly draw H atoms
Predict the products of the following reaction.