Tandem cationic aza-cope rearrangement-Mannich cyclization approach to the core structure of FR901483 via a Bridgehead iminium ion.

[reaction in text] An approach to the potent immunosuppressant FR901483 is described. This route utilizes a tandem cationic aza-Cope rearrangement-Mannich cyclization to generate the core structure of this compound. In addition, this is the first demonstration of this tandem reaction passing through a bridgehead iminium ion.