Phorbol : Uber die Wirkstoffe des Crotonöls, VII

The preparation of phorbol C₂₀H₂₈O₆ from croton oil and of some functional derivatives is described. The six oxygen functions of phorbol are identified as five hydroxyl groups and one carbonyl group. Two C=C double bonds are part of primary allylalcoholic and α,β-unsaturated carbonyl groupings. The carbon skeleton contains four rings and the parent hydrocarbon is most probably of diterpene nature.