Chemical and x-ray structural investigation of a new diterpene lactone betolide

A crystalline substance with the composition C20H24O5 has been isolated from the roots of common betony. The spatial structure of this new diterpene lactone, betolide, has been established from the results of UV, IR, NMR, and13C NMR spectral and x-ray structural investigations — 13-formyl-14-hydroxy-(2′-hydroxy-5′-oxotetrahydrofuro) [3′,4′:11,12′]-Δ8,10,12-podocarpane, the first representative of new tetracyclic diterpenes the lactone ring of which is formed with the participation of a hydroxyl of a geminal diol. The stability of a lactone ring of this type and a high reactivity of the semiacetal hydroxyl have been shown.