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

Give the product of the aldol condensation in Figure 3

Cc.48.

Cinnamaldehyde may be synthesized through aldol condensation reaction of two aldehydes Q and R as shown below. 1. 10% NaOH add R slowly H. т 5°C heat (-H2O) Cinnamaldehyde Suggest structures for aldehydes Q and R. Identify which one will form the enolate ion and draw the structure (both resonances). а. b. Show the nucleophilic attack by the enolate on the other aldehyde and draw the structure of the B-hydroxyketone T produced. с. Show the formation of the a,ß-unsaturated ketone when a molecule of water is lost in the dehydration step.

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…

Retro aldol: H. NaOH H₂O H. HTH "j"82f NaOH

K86.

Cinnamaldehyde may be synthesized through aldol condensation reaction of two aldehydes Q and R as shown below. 1. 10% NaOH add R slowly 5°C heat (-H20) Q Cinnamaldehyde Suggest structures for aldehydes Q and R. Identify which one will form the enolate ion and draw the structure (both resonances). а. b. Show the nucleophilic attack by the enolate on the other aldehyde and draw the structure of the B-hydroxyketone T produced. Show the formation of the a.ß-unsaturated ketone when a molecule of water is lost in the dehydration step. C.

What conjugate base must be formed during the E1cb mechansim in an aldol condensation reaction running under basic conditions? А. enol В. B-hydroxy carbonyl C. a,B-unsaturated carbonyl D. enolate

The reaction below is a base-catalyzed aldol reaction. O || CH₂-C-H CH3-C-H Ethanal (Acetaldehyde) H I CH3-C-H Ethanal (Acetaldehyde) NaOH Draw curved arrows to show the movement of electrons in the step of the mechanism shown below. Arrow-pushing Instructions AC⇒x= :O: || :CH₂-C-H OH Bl CH3-CH—CH2-CH -CH₂-1-1 a 3-Hydroxybutanal (B-hydroxyaldehyde; formed as a racemic mixture) :0: :0: || CH3—CH—CH2-C-H A tetrahedral carbonyl addition intermediate X