STRUCTURES OF ANISATIN AND NEOANISATIN - TOXIC SESQUITERPENES FROM ILLICIUM ANISATUM L

Two toxic compounds, anisatin (I) and neoanisatin (XXV) were isolated from Illicium Anisatum L. Extensive studies on noranisatin (II), an oxidation product of I were carried out by chemical and spectral methods. Two dihydrocoumarins (XI, XII) were obtained by stepwise degradation of II, the structures of which were firmly established. On the basis of the structures of XI and XII together with spectral evidence of important derivatives such as VII, VIII, IX and XV, the structure of II was determined as IIk. Based on the structure of II, anisatin was represented as If, which contains a stable β-lactone. The structure of neoanisatin was established as XXVa by a variety of oxidation reactions: a common oxidation product VII was obtained from both natural products, I and XXV. Some of the reactions of special interest are illustrated. © 1977.