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Question: Acid-catalyzed dehydration of β-hydroxy carbonyl compounds occurs by the mechanism discussed in Section 9.8. With this in mind, draw a stepwise mechanism for the following reaction.

Question:What starting materials are needed to synthesize each compound by a crossed Claisen reaction?

Question:Even though B contains three ester groups, a single Dieckmann product results when B is treated with $\mathit{N}\mathit{a}\mathit{O}\mathit{C}{\mathit{H}}_{\mathbf{3}}$in $\mathit{C}{\mathit{H}}_{\mathbf{3}}\mathit{O}\mathit{H}$, followed by ${\mathit{H}}_{\mathbf{3}}{\mathit{O}}^{\mathbf{+}}$. Draw the structure and explain why it is the only product formed.

Question:Draw the product formed from a Michael reaction with the given starting materials using$\mathit{O}\mathit{E}\mathit{t}\mathbf{,}\mathbf{}\mathit{E}\mathit{t}\mathit{O}\mathit{H}$.

Question: Draw the product of each Robinson annulation from the given starting materials using $\mathit{O}\mathit{H}$in ${\mathit{H}}_{\mathbf{2}}\mathit{O}$solution.

Question:What starting materials are needed to synthesize each compound using a Robinson annulation?

Question: What product (including stereochemistry) is formed in each of the following intramolecular reactions?

Question: What aldehyde or ketone is needed to prepare each compound by an aldol reaction?

Question: In theory, the intramolecular aldol reaction of 6-oxoheptanal could yield the three compounds shown. It turns out, though, that 1-acetylcyclopentene is by far the major product. Why are the other two compounds formed in only minor amounts? Draw a stepwise mechanism to show how all three products are formed.

Question: Draw a stepwise mechanism for the following Robinson annulation. This reaction was a key step in a synthesis of the steroid cortisone by R. B. Woodward and co-workers at Harvard University in 1951.