catalytic hetero-Diels―Alder― allylboration sequence and a ruthenium-catalyzed isomerization of an allylic alcohol moiety as key steps open a new route for the asymmetric synthesis of 6,8-dioxabicyclo[3.2.1]octane subunits. The application of this strategy to the synthesis of (+)-iso-exo-brevicomin is also reported.