Suggest a reasonable mechanism for one of the following reactions:

solved problems: aldehydes and ketones


SOLUTION:

solution

The first stage consists of opening the oxacyclopropane on the least substituted carbon.

solution

In the second stage, the transfer of the oxygen pair eliminates the chlorine, forming a carbonyl. In the first step there are two possible attack positions; carbonyl carbon and chlorine carbon. Since the final product has no methoxide on the chlorine carbon, we attack the carbonyl. In the second stage, an intramolecular nucleophilic substitution occurs. To finish the methoxide open the epoxide.