Synthesis of Pseudopelletierine, Mannich reaction base catalysed
You are very close. The only issue I see is that the Mannich reaction takes place between an enol(ate) and an imine (iminium). Your mechanism goes to the hemiaminal, and then the enolate must displace a hydroxide leaving group. Essentially that's an SN2 with a hydroxide as a leaving group, which does not occur. Instead, from the hemiaminal, the nitrogen kicks out the hydroxide to form an iminium, which is a much more reactive electrophile. The enolate attacks readily. Repeat that process, decarboxylate &amp; tautomerize twice, and you're there.