3-hydroxybutanal can exist in equilibrium as a cyclic hemiacetal.

Question

Quizplus · Accepted Answer

3-hydroxybutanal cannot form a cyclic hemiacetal because it does not contain a carbonyl and an alcohol group within the same molecule that are properly positioned to react and form a cyclic structure. Hemiacetals are typically formed when an aldehyde and an alcohol react, and a cyclic hemiacetal requires a single molecule to contain both functional groups in such a way that allows for the formation of a ring structure, usually 5 or 6 members for stability. 3-hydroxybutanal has an aldehyde group and an alcohol group, but they are not capable of forming a stable cyclic structure due to their positions in the molecule.

3-Hydroxybutanal Can Exist in Equilibrium as a Cyclic Hemiacetal