Total synthesis of sordaricin

The total synthesis of sordaricin, the diterpene aglycone of an important class of antifungal compounds, is described. Two approaches were explored, the first of which utilized a possible biogenetic intramolecular [4 + 2] cycloaddition to form the complete carbon skeleton of the target molecule. A second approach using a tandem cycloreversion/intramolecular [4 + 2] cycloaddition sequence is also detailed.