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Question: Draw the aldol product formed from each compound.

Question: What carbonyl starting materials are needed to prepare each compound using a directed aldol reaction?

Question: Zingerone, a spicy-sweet component of cooked ginger, can be converted to its protected TBDMS ether A, as we learned in Chapter 20. How can A be converted to gingerol, a compound present in fresh ginger, using a directed aldol reaction as a key step?

Question: A key step in the synthesis of donepezil (trade name Aricept) is a directed aldol reaction that forms $\mathit{Î\pm }\mathbf{,}\mathit{β}$-unsaturated carbonyl compound X. What carbonyl starting materials are needed to prepare X using a directed aldol reaction? What reagents are needed to convert X to donepezil?

Question: Draw a stepwise mechanism for the conversion of heptane-2,6-dione to 3-methylcyclohex-2-enone with NaOEt, EtOH.

Question: What cyclic product is formed when each 1,5-dicarbonyl compound is treated with aqueous $\mathit{O}\mathit{H}$?

Question: Following the two-step reaction sequence depicted in Figure 24.5, write out the steps needed to convert A to B.

Question: What β-keto ester is formed when each ester is used in a Claisen reaction?

Question: What crossed Claisen product is formed from each pair of compounds?

a.

b.

Question: Avobenzone is a conjugated compound that absorbs ultraviolet light with wavelengths in the 320–400 nm region, so it is a common ingredient in commercial sunscreens. Write out two different crossed Claisen reactions that form avobenzone.