Identify all resonance forms of the enolate formed, and indicate whether or not a substantial amount of starting ketone will be present together with the enolate at equilibrium. (select all that apply) °° No, there will NOT be a substantial amount of diketone present after equilibrium has been established. Yes, there will be a substantial amount of diketone present after equilibrium has been established.

0 0 B What is the strongest nucleophile in this list? B OH D

4. An enzyme (acetoacetate decarboxylase) catalyzes the decarboxylation of acetoacetate. The mechanism has been studied extensively; concluding that the key bond-breaking step involves an enamine as a leaving group. Draw a curved arrow mechanism in the boxes below. Label the "iminium” and then "enamine" and then "iminium" as three consecutive intermediates in the mechanism. Note that the acid is stoichiometric PLUS catalytic. (Hint: acid-base involving oxygen should be drawn concerted with other steps) Enz (cat.) NH2 EnzAH EnzAH (cat.) O=U=0 Θ EnzA

The trityl cation intermediate is a highly stable species due to the resonance stabilization provided by the phenyl rings. Please draw these resonance structures.

Rank the following intermediates in order of increasing stability.

Answer the following questions concerning ketones. (I narrowed it down to only 3 subparts)

Draw the most stable resonance form for the intermediate in the following electrophilic substitution reaction. OH CH3 + + H3C CH₂ CH3 First stage in synthesis of the preservative BHT • You do not have consider stereochemistry. • Include all valence lone pairs in your answer. • In cases where there is more than one answer, just draw one. ▼ H3PO4 ? OH CH3 CH3 CH3 CH3

9:11 Question 13 of 20 Submit Br NaOH heat Draw E1 Major Product + Draw Minor E1 Product

5) Only one product is observed in this reaction. Draw the product and briefly explain why. Hint: It is NOT due to the Zaitsev rule. H3PO4 OH H₂O

Draw the major product formed for each reaction. Assume the reactions are irreversible. Include stereochemistry when products contain stereocenter(s). It may be helpful to first identify whether the reaction is a substitution (and SN1 or SN2), an elimination (and E1 or E2) or a carbonyl addition. (a) 1 equiv means for every molecule of substrate, there is one molecule of NaOCH3 Br Br NaOCH 3 (1 equiv) 0 °C (b) Draw only the substitution product. Both elimination and substitution occur here. (၁) CH3 Br Br CH3OH NaOCH3 80 °C (d) "Then" means CHзl is added after the Grignard reacts. H3C MgBr (1 equiv) then CH3l