Identifizierung von Farnesol als Zwischenstufe in der Biosynthese des Cantharidins aus Mevalonsäurelacton. 7.Mitteilung zur Biosynthese des Cantharidins

Abstract
Identification of farnesol as an intermediate in the biosynthesis of cantharidin from mevalonolactoneSimultaneous injection of 2‐[14C]‐mevalonolactone (2‐[14C]‐1) and (E,E)‐11′,12‐[3H]‐farnesol (11′,12‐[3H]‐2) into Lytta vesicatoria L. (Coleoptera, Meloidae) yields doubly labelled cantharidin (3). The remainder of the precursor farnesol, re‐isolated from the insects after the incubation period, has incorporated 14C‐radioactivity. The labelling pattern in this farnesol, as determined by two independent degradative reaction sequences, is in agreement with the isoprene rule. Since specific incorporation of farnesol (2) into cantharidin (3), and of mevalonolactone (1) into both, farnesol (2) and cantharidin (3) is observed, the sesquiterpene alcohol 2 acts as an intermediate in the biosynthesis of the C10‐compound 3 (Scheme 1).