Review Topics [References] The Robinson annulation is a combination of two carbonyl coupling reactions, the Michael reaction and the intramolecular aldol condensation. The most common partners in the reaction are a nucleophilic donor (such as a cyclic ketone, a B-keto ester, an enamine, or a B-diketone) and an a,B-unsaturated ketone acceptor. The product is a substituted 2-cyclohexenone derivative. Draw the structures of the nucleophilic pyrrolidine enamine and the aB-unsaturated ketone acceptor that were combined in a Robinson annulation to give the following product P. O opy ate C P opy ste

Review Topics [References] The Robinson annulation is a combination of two carbonyl coupling reactions, the Michael reaction and the intramolecular aldol condensation. The most common partners in the reaction are a nucleophilic donor (such as a cyclic ketone, a B-keto ester, an enamine, or a B-diketone) and an a,B-unsaturated ketone acceptor. The product is a substituted 2-cyclohexenone derivative. Draw the structures of the nucleophilic pyrrolidine enamine and the aB-unsaturated ketone acceptor that were combined in a Robinson annulation to give the following product P. O opy ate C P opy ste

Organic Chemistry: A Guided Inquiry

2nd Edition

ISBN:9780618974122

Author:Andrei Straumanis

Publisher:Andrei Straumanis

Chapter26: Aldol And Claisen Reactions

Section: Chapter Questions

Problem 5E

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The Robinson annulation is a combination of two carbonyl coupling reactions, the Michael reaction and the intramolecular aldol condensation. The most common partners in the reaction are a nucleophilic donor (such as a cyclic ketone, a ß-keto ester, an enamine, or a ß-diketone) and an a,ß-unsaturated ketone acceptor. The product is a substituted 2-cyclohexenone derivative. il The above reaction between a ß-keto ester and an a,ß-unsaturated ketone yields a product containing a 2- cyclohexenone ring. One of the steps of this reaction follows. Draw curved arrows to show the movement of electrons in this step of the mechanism. Arrow-pushing Instructions AC↔XT я OEt -I H OEt CO₂Et Eto: يز OEt EtOH
1. Provide structures for the products and/or starting materials for the following reactions. Donor Acceptor NaOH CH₂CH₂OH heat loss of H₂O H3C mixed-aldol condensation product NaOH CH₂OH heat *) NOE EtOH #40 2) H₂O* ΕΙΟ CH₂ mixed-Claisen condensation product +HgC. H3C CHS H loss of H₂O mixed-aldol condensation product H3C людете CH3 NaOEt loss of H₂O intramolecular aldol condenstation cyclization product
Draw the major product of this aldol addition reaction. Ignore inorganic byproducts. 1. LDA 2. C6H11CH2CHO 3. Neutralizing work-up Drawing Q
The Robinson annulation is a combination of two carbonyl coupling reactions, the Michael reaction and the intramolecular aldol condensation. The most common partners in the reaction are a nucleophilic donor (such as a cyclic ketone, a B-keto ester, an enamine, or a B-diketone) and an a,8-unsaturated ketone acceptor. The product is a substituted 2-cyclohexenone derivative. The above reaction between a enamine and an a,B-unsaturated ketone yields a product containing a 2-cyclohexenone ring. One of the steps of this reaction follows. Draw curved arrows to show the movement of electrons in this step of the mechanism. Arrow-pushing Instructions H-A A OH HO Nest Emal Instructor Save and Ex
The Robinson annulation is a combination of two carbonyl coupling reactions, the Michael reaction and the intramolecular aldol condensation. The most common partners in the reaction are a nucleophilic donor (such as a cyclic ketone, a β-keto ester, an enamine, or a β-diketone) and an α,β-unsaturated ketone acceptor. The product is a substituted 2-cyclohexenone derivative. Draw the structures of the nucleophilic β-keto ester and the α,β-unsaturated ketone acceptor that were combined in a Robinson annulation to give the following product: Draw the β-keto ester as an ethyl ester,
The Robinson annulation is a combination of two carbonyl coupling reactions, the Michael reaction and the intramolecular aldol condensation. The most common partners in the reaction are a nucleophilic donor (such as a cyclic ketone, a β-keto ester, an enamine, or a β-diketone) and an α,β-unsaturated ketone acceptor. The product is a substituted 2-cyclohexenone derivative. Draw the structures of the nucleophilic β-diketone and the α,β-unsaturated ketone acceptor that were combined in a Robinson annulation to give the following product:
Fill in the missing reagents a-e in the following scheme:
This reaction is an example of conjugate addition of a nucleophile to an a,ß-unsaturated carbonyl. LOCH3 H20 H3C H3C° OCH3 OCH3 Draw the two resonance structures of the enolate anion intermediate for this reaction.
resource from Cengage Learning - Google Chrome ssignment/takeCovalentActivity.do?locator=assignment-take e by the Aldol Condensation (References) OH base + H,0 heat H. H3C H. The aldol reaction is a carbonyl condensation reaction between two carbonyl partners and involves a combination of nucleophilic addition and a-substitution steps. One partner is converted into an enolate ion nucleophile and adds to the electrophilic carbonyl group of the second partner. In the classic aldol reaction, the carbonyl partners are aldehydes or ketones, although aldehydes are more reactive. The product is a B-hydroxy carbonyl compound. In the mixed aldol reaction, the best results are obtained when one of the partners does not have an a-hydrogen. It cannot form an enolate anion and can therefore not undergo self-reaction. The enolizable aldehyde is added slowly to a basic solution of the first aldehyde so that the mixed product is preferentially formed. Under reaction conditions slightly more vigorous…
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