Since hemiacetals are unstable,they are seldom found in significant quantities in reaction mixtures.An exception to this statement is the formation of hemiacetals
A)from carbonyl compounds and alcohols with identical R groups.
B)from aldehyde and alcohol groups within the same molecule.
C)from carbonyl compounds and alcohols with different R groups.
D)in an acid-catalyzed reaction.
E)in a base-catalyzed reaction.

Question

Quizplus · Accepted Answer

Hemiacetals can be stable when formed from aldehyde and alcohol groups within the same molecule, known as intramolecular hemiacetal formation. This occurs because the hemiacetal product is held in a cyclic form that can minimize the loss of water and stabilize the molecule. In contrast, intermolecular hemiacetal formation between carbonyl compounds and alcohols with different R groups is less stable and occurs less frequently. Acid-catalyzed and base-catalyzed reactions can facilitate hemiacetal formation, but they do not necessarily increase the stability of hemiacetals. Therefore, the best choice is B, which describes the specific circumstance where hemiacetals can be stable.

Since Hemiacetals Are Unstable,they Are Seldom Found in Significant Quantities