Spiroleptosphol isolated from Leptosphaeria doliolum.

A novel gamma-methylidene-spirobutanolide spirolephtoshol (1) was isolated from ascomycetous fungus Leptosphaeria doliolum as a cytotoxic compound. The relative structure was established by the NMR analysis involving the NOE experiments. Absolute structure of the bicyclic moiety was determined by chemical derivation followed by the CD analysis.

Syntheses of lambertellols and their stable analogues; investigation of the real active species in the mycoparasitism by Lambertella species.

Lambertellols A (1) and B (2), isolated from mycoparasites Lambertella species, were synthesized. The synthesis features intramolecular aldol-type cyclizations of aldehydes 12 and 14 and site specific oxidations of 1-hydroxylambertellols as key steps. The synthesis also provided all diastereomers of 1-hydrolambertellols 17-19 and 25.