Sequential α‐Aminoalkyl Radical and Oxygen‐Centered Radical Reactions of Vinyl Bromide‐Tethered Tricyclic Lactones

Tricyclic lactone compounds featuring a vinyl bromide tether were investigated for intramolecular radical cyclization. α-Aminoalkyl radicals, generated through the translocation of an initially generated vinyl radical, underwent cyclization or cyclization/1,5-hydrogen transfer, C─O bond fragmentation, and further cyclization to construct the nitrogen-containing heterocyclic rings. When two diastereomers with substituents in opposite stereochemical configurations underwent radical reactions separately, they yielded distinct products. Density functional theory (DFT) calculation studies were carried out to unravel mechanistic insights in this process.