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

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

1. Provide the mechanism of the reaction shown in the picture. 2. Explain why it cannot be done in basic conditions. 3. Why is the enol tautomer favored over the keto tautomer?

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

D2. Draw the reaction full mechanism for TPCP. Carbanion Enolate HO Dibenzylacetone Benzil Conjugated enone но Carbanion Enolate 0-? ? Conjugated enone

Give the likely product for the following Aldol addition reaction. Select Draw Rings More Erase H. NaOH H30 of

ArSO,H Draw curved arrows to show the movement of electrons in the following step of an acid-catalyzed aldol condensation reaction. Arrow-pushing Instructions Hjö: H-Ö- -Ar H. Ar O=h=0

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d. Draw arrow-pushing mechanism for an enzymatic retro-aldol reaction of the following hexose. Use B: and/or HA as needed. ОН OH OH мен ОН ОН ОН