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?

Show how the following compounds can be synthesized. The only carbon-containing compounds available to you for each synthesis are shown.

b.

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

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

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

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

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