Skeletal rearrangements of bicyclo[2.2.2]lactones: a short and efficient route towards Corey's lactone

The application of a unique tandem radical-initiated, Brönsted acid-catalysed, skeletal rearrangement of bicyclo[2.2.2]lactones provides a novel route towards Corey's lactone 2. The strategy also features a high-pressure promoted inverse electron-demand Diels-Alder (IEDDA) reaction of 3-carbomethoxy-2-pyrone (3-CMP), which proceeds with complete regio- and diastereocontrol.