An enantio- and diastereocontrolled synthesis of two monoterpenes having a 2,8-dioxabicyclo[3.3.1]nonane
framework, (-)-semburin and (-)-isosemburin, isolated from Swertia japonica, has been developed starting from the chiral building block having a 7,8-dioxabicyclo[3.2.1]octane
framework.
chiral building block - intramolecular ene reaction - monoterpene - 7,8-dioxabicyclo[3.2.1]octane
framework - 2,8-dioxabicyclo[3.3.1]nonane framework