Synthetic Entry to the 2‑Azatricyclo[4.3.2.0^4,9]undecane Ring System via Tropone

A synthesis of the 2-azatricyclo­[4.3.2.04,9]­undecane
ring systema hitherto unreported bridged azatricyclic ring
systembeginning from tricarbonyl­(tropone)iron and allylamine
was accomplished in three steps: (1) aza-Michael addition of allylamine
to tricarbonyl­(tropone)­iron; (2) Boc-protection of the resulting secondary
amine; and (3) oxidative demetallation leading to a spontaneous intramolecular
Diels–Alder reaction. The effect of a variety of parameters
on the intramolecular Diels–Alder reaction was investigated,
including diene and dienophile substitution patterns and dienophile
tether length.