Chem 334 1st Edition Lecture 20Outline of Last Lecture I. Condensation and conjugate addition reactions of carbonyl compoundsOutline of Current Lecture II. Intermolecular AldolsIII. Claison CondensationIV. Dieckman CondensationCurrent LectureIntermolecular aldols: O O -OH O- H+/wkup OH O OSometimes you can use ketones as an electrophile, even though they’re not very good electrophiles O O- -OH H+/Δ H O O OUsing esters as enolates and electrophiles:Claisen Condensation: O 1. EtO- O O O (2 equivalence) 2. H+ wkup O The product of this reaction is a beta-keto ester. The reason we use EtO- and not –OH or –MeO in this reaction is because we have to match the side are of the ester, otherwise you get hydrolysis (when you use OH) or transesterification (when you use MeO)These notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute. OOWe need two hydrogen alpha to ester for the reaction to work under weak base conditions: O MeO- O No Reaction H O 1. EtO- O O 1. –OH O O (2 equiv.) 2. H+ wkup O 2. H+ wkup 3. ΔDieckman condensation:A dieckman condensation reaction is an intramolecular claisen reaction which makes a five or six membered ringO EtO- O- O H+/wkup O O O OO O
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