Propose a mechanism to show how cyclopentanone reacts with piperidine in the presence of an acid.

Mechanism of cyclopentanone reacting with piperidine in acid, showing imine and enamine formation.

Detailed mechanism of cyclopentanone and piperidine reaction, illustrating imine and enamine structures.

Cyclopentanone and piperidine reaction mechanism, highlighting imine and enamine formation steps.

Illustration of cyclopentanone and piperidine reaction mechanism, focusing on imine and enamine pathways.