A short and efficient synthesis of the antitumor diterpenoid(+)-zerumin B has been accomplished starting from (+)-sclareolide. At the heart of the synthetic strategy lies theregioselective formation of the α-substituted γ-hydroxybutenolide moiety of zerumin B. This was achieved by meansof a [1,4] O→C triisopropylsilyl migration followed bysinglet oxygen (1O2) oxidation of the resulting 2-triisopropylsilyl-3-(α-hydroxy)alkylfuran.