1. Aldol reactions (condensation of two aldehydes or ketones to yield a ẞ-hydroxy carbonyl) can go inreverse (B-hydroxy carbonyl to two aldehyde/ketones, a retro-aldol). Propose mechanisms for thefollowing two transformations, using both intra-molecular aldol and a retro-aldol reactions. Be sureto follow the rules we have discussed for writing reaction mechanisms!H₂C.H&C.Na+ -OEtethanolH₂C-H₂C. HONa OEtethanol

However, I can provide some general information about these reactions and point you to some…

Answered: 1. Aldol reactions (condensation of two…

Organic Chemistry

9th Edition

ISBN:9781305080485

Author:John E. McMurry

Publisher:John E. McMurry

Chapter23: Carbonyl Condensation Reactions

Section23.SE: Something Extra

Problem 56AP

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I H H3C NOC XT :0: MET H₂C base H3C 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 ß-hydroxy carbonyl compound. H OH q H3C H₂C H Under reaction conditions slightly more vigorous than those employed for the aldol reaction, the ß-hydroxyl group is eliminated in an E1cB dehydration to give an a,ß-unsaturated carbonyl compound. Draw curved arrows to show the movement of electrons in this step of the mechanism. Arrow-pushing Instructions heat H H + H₂O
2 H3C H3C H C→XT OH H3C 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 ß-hydroxy carbonyl compound. base :0: OH H H Under reaction conditions slightly more vigorous than those employed for the aldol reaction, the ß-hydroxyl group is eliminated in an E1cB dehydration to give an a,ß-unsaturated carbonyl compound. Draw curved arrows to show the movement of electrons in this step of the mechanism. Arrow-pushing Instruct ns H3C heat OH H3C :0: H + H₂O H
2 Moin H3C H H₂C C⇒x= base :0: OH Hori 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. Under reaction conditions slightly more vigorous than those employed for the aldol reaction, the ß-hydroxyl group is eliminated in an E1cB dehydration to give an a,ß-unsaturated carbonyl compound. Draw curved arrows to show the movement of electrons in this step of the mechanism. Arrow-pushing Instructions H₂C Ἡ :0: heat H Home H3C + H₂O
2 CH3COOCH,CH3 C2H5O'K*/C2H5OH ---> CH3COCH,COOCH,CH3 [+] Hofmann elimination Clemmensen reduction Claisen condensation O Cannizzaro reaction O Aldol condensation
d. 4. Provide a step-by-step synthesis for the following conversions. Provide all reagents used in each step. OH OH HO. OH ОН
Show all the processes in the mechanism of the reaction.
10. Give the mechanism for the aldol reaction of the given enolate and acetaldehyde, show the aldol product. NB: Show all arrows. Li OTBS H م کی داماد Me OTBS Me Enolate o=/ 26
Three reactions between a Grignard reagent and a carbonyl compound are given. Draw the main organic product for each reaction and indicate if H+ or H¯ is needed to complete each reaction. The starting material structures are provided in the answer fields as a starting point for your drawings. The first reaction involves a ketone. 1. CH₂MgBr 2. H+ or H™? Select Draw / |||||| C Rings O More Erase
base 2 H3C H H3C OH heat H H3C + H₂O 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 ẞ-hydroxy carbonyl compound. Under reaction conditions slightly more vigorous than those employed for the aldol reaction, the ẞ-hydroxyl group is eliminated in an E1CB dehydration to give an a,ẞ-unsaturated carbonyl compound. Draw curved arrows to show the movement of electrons in this step of the mechanism. Arrow-pushing Instructions X :OH H₂O: а کی H₂C H H₂C H H
Q6. Propose a mechanism, using curved arrows, for the base-catalysed aldol reaction and the subsequent dehydration between furfural and cydahexanene КОН H
4) When a mixture of two different compounds both containing a hydrogens are placed under acidic or basic conditions, crossed aldol products can be formed. By either self-condensation or cross condensations. Draw the 4 aldol and 4 a.B-unsaturated ketones that can be made from the following mixed system. -OH 4 products One way to control this is by either having only one compound with a hydrogens or by reacting the desired nucleophile with lithium diisopropylamide (LDA) before addition of second carbonyl. The issue here is that this reaction stops at the aldol unless excess base is used. он LDA OH heat Show a synthetic scheme of how to use the following carbonyls to control the formation of each cross product (i.e. each as nucleophile and electrophile, two reactions). and
4. Draw the aldehydes needed to prepare the compound below by an aldol reaction. OH CHO From: ogynu abmu and Vo

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