Lecture 36 - alpha-Reactivity and Condensation Reactions. As in many synthetic procedures, an important challenge in ketone alkylation is choosing reagents and conditions that allow control of isomerism and of
single vs. multiple substitution. β-Dicarbonyl compounds allow convenient alkylation and preparation of ketones and carboxylic acids. The aldol condensation, in which an α-position adds to a carbonyl group to
generate a β-hydroxy- or an α,β-unsaturated carbonyl compound, can be driven to completion by removal of water. The Robinson annulation reaction is an important example of conjugate addition to
α,β-unsaturated carbonyl compounds. α-Acylation of esters as in the Claisen condensation is a key step in the biosynthesis of fatty acids. Determining the constitutional structure of sugars posed a daunting
challenge to early carbohydrate chemists. (from oyc.yale.edu)
Lecture 36 - alpha-Reactivity and Condensation Reactions
Time
Lecture Chapters
[00:00:00]
1. The Soxhelet Extractor
[00:08:44]
2. Alkylation Regiochemistry
[00:16:35]
3. Alkylation of β-Dicarbonyl Compounds
[00:22:12]
4. Aldol Condensations
[00:29:41]
5. Conjugate Addition and Robinson Annulation
[00:44:17]
6. Claisen Condensation and Fatty Acid Biosynthesis
[00:49:36]
7. Carbohydrate Structures
References
Lecture 36 - alpha-Reactivity and Condensation Reactions
Instructor: Professor J. Michael McBride. Resources: Professor McBride's website resource for CHEM 125b (Spring 2011). Transcript [html]. Audio [mp3]. Download Video [mov].