Final answer:
Cyanohydrins can be reconverted to carbonyl compounds through reverse nucleophilic addition, involving processes like hydration and oxidation, and sometimes requiring enzymatic or chemical catalysis.
Step-by-step explanation:
Cyanohydrins can be reconverted to carbonyl compounds through a process akin to reverse nucleophilic addition. Initially, the nucleophilic cyanide ion adds to a carbonyl compound, resulting in a cyanohydrin. To revert this process and regenerate the carbonyl compound, the cyanide and hydroxyl group must be removed.
One mechanism involves the hydration of the cyanohydrin to form imines, which can then be hydrolyzed back into carbonyls. Another approach utilizes oxidation, wherein the alcohol portion of the cyanohydrin is first transformed into an aldehyde, which then gets oxidized into a carboxylic acid. Subsequent decarboxylation (especially in ß-keto acids) can regenerate the carbonyl compound at more moderate temperatures.
The overall conversion is facilitated by enzymes or chemical catalysts under specific conditions, such as the presence of certain reagents or under high temperatures necessary for facilitating decarboxylation or other reaction mechanisms that reverse the cyanohydrin structure back to the original carbonyl group.