Ch. 22 - Condensation ChemistryWorksheetSee 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

1,5-dicarbonyl compounds generated from the Michael Reaction (enone + enolate) have the ability to undergo intramolecular self-condensation into 6-membered enones. Are you impressed yet?

Concept #1: Robinson Annulation

Example #1: Predict the Major Product

Practice: Provide the product for the following Robinson Annulation Reaction.

If you noticed a methyl group that vanished around 3:50 in the above video, you are not alone! Place a methyl there in your final answer and you will be good :)

Practice: How would you prepare the following compound using a Robinson annulation reaction between a di-ketone and an alpha, beta unsaturated ketone? 

Practice: How would you prepare the following compound using a Robinson annulation reaction between a ketone and an alpha, beta unsaturated ketone? 

Great job, guys! You survived. 

Additional Problems
A scientist needed to prepare large quantities of chemical intermediate I through the process shown below. What is the structure of intermediate  I?
In the following Robinson Annulation, compound A could be formed but is not a final product of the reaction. Why? a) A is formed irreversibly, but only in small amounts contributing to a lower yield of the reaction. b) A is too strained and is never formed. c) A is formed reversibly, but cannot undergo elimination, so it reverts back the prior intermediate. d) A can only be formed from the less favorable enolate and is therefore only a minor product of the reaction. e) The bonds in A are way too long and a molecule would never want to look that silly, so it doesn’t form.
Draw the intramolecular condensation product formed when 2,6-heptanedione is heated with aqueous sodium hydroxide.
Draw the product for the following Robinson reaction.
Predict the product of the following reaction
 Provide a mechanism for the following transformation. Show all important flows of electrons, charges and intermediates. Where indicated, (in the structure-n-a- box)- draw the intermediates.
For the following reaction, two products are formed, in addition to water. If the oxygen of the enone is labeled with an isotope (18O for example), where will the label appear in the product? a) B and E only b) B and D only c) A and C only d) A, B, C, and D e) all 5 positions
Illlustrate the Robinson Annulation. Show two typical reactants and the resulting product and indicate where the atoms from the starting material end up in the product. A full mechanism is not necessary.
Complete the mechanism for the following Robinson Annulation Reaction. Draw all the arrows to indicate movement of all electrons, write all lone pairs, all formal charges, and all products for each step. If a new chiral center is created in an intermediate or in the product indicate with an * (ASTERIK).
Provide a mechanism for the following transformation. Show all important flows of electrons, charges and intermediates. Where indicated, (in the structure-n-a-box) draw the intermediates.
Provide the missing starting material, reagent, or major product in the box provided.
Which two components can be used to prepare the following compound through a Robinson annulation reaction?