Stereospecific synthesis of Conduramine-F4 and Conduritol-F has been a
chieved by fully stereospecific cyloaddition of singlet oxygen to cycl
ohexadiene ketal 1 followed by reductive extrusion of one oxygen atom.
The obtained monoepoxide 3 has been smoothly opened to conduritol-F4
and conduramine-F4 6 by water and ammonia, respectively.