I have a problem on fragmentation which requires mechanisms involving formation of an enamine from a cyclic ketone and cyclic secondary amine. This then reacts with a cyclic aldehyde via conjugate addition, but the intermediate cannot be reached.
I've been told that I have to exchange the enamine of the ketone with the enamine of the aldehyde. What does this mean?
Give mechanisms for these reactions, commenting on the fragmentation.
Purpose of the problem
Revision of conjugate addition of enols, another ring expansion with an enolate as leaving group and an interesting piece of stereochemistry.
The first step is enamine formation and the second is conjugate addition. This appears to lead to a dead end as we cannot find a way to make the intermediate from the product.