25. Condensation Chemistry

Which of the following best describes the major product formed when $\mathrm{cyclopentanone}$ undergoes aldol condensation under basic conditions?

In an aldol condensation reaction between an $\mathrm{aldehyde}$ and a $\mathrm{ketone}$, why is an excess of $\mathrm{aldehyde}$ often used?

What is the major organic product formed when two molecules of ${\mathrm{CH}}_3\mathrm{CHO}$ (acetaldehyde) undergo an aldol addition under basic conditions?

Which compound is formed as the major product when two molecules of ${\mathrm{CH}}_3\mathrm{CH}$₂CHO (butanal) undergo aldol condensation in the presence of base?

Which aldol addition product is formed when two molecules of ${\mathrm{CH}}_3\mathrm{CHO}$ (acetaldehyde) undergo base-catalyzed aldol condensation?

What is the primary purpose of adding base in the aldol condensation reaction? Choose the best answer.

Which of the following lists all four possible $\beta$-hydroxy aldehydes that can be formed by a crossed aldol reaction between ${\mathrm{CH}}_3{\mathrm{CH}}_2{\mathrm{CH}}_2\mathrm{CHO}$ and $C_6{H}_5{\mathrm{CH}}_2\mathrm{CHO}$?

Which of the following best describes the major product formed when $3-\mathrm{methylbutanal}$ undergoes aldol condensation under basic conditions?

In an aldol addition reaction, what is the typical product formed before any dehydration occurs?

Which major product is formed when $\mathrm{benzaldehyde}$ reacts with $\mathrm{acetone}$ in the presence of $\mathrm{sodium} \mathrm{hydroxide}$ in an $\mathrm{aldol} \mathrm{condensation}$ reaction?

Which of the following is the major enone product formed from the aldol self-condensation of ${\mathrm{CH}}_3\mathrm{COCH}{2}_2\mathrm{CH}{3}_3$ (3-pentanone) under basic conditions, followed by dehydration?

Which statement best explains why $\mathrm{aldol}$ reactions involving $\mathrm{ketones}$ typically give low yields?

What product can be isolated from the following aldol condensation reaction?