When is a crossed Aldol reaction said to be synthetically useful?

Question

Quizplus · Accepted Answer

A crossed Aldol reaction is said to be synthetically useful when one carbonyl compound has no alpha hydrogens, as this prevents the possibility of self-condensation. This allows for selective formation of the desired aldol product. Options A and B are incorrect because having fluorine atoms does not affect the usefulness of the reaction. Option D is incorrect as it mentions beta hydrogens, which are not relevant to the selectivity of the reaction.

When Is a Crossed Aldol Reaction Said to Be Synthetically α\alphaα

When Is a Crossed Aldol Reaction Said to Be Synthetically $\alpha$