ISOVELLEROL AND NEW ISOLACTARANE SESQUITERPENES, THEIR STRUCTURE AND ANTIFEEDANT ACTIVITY

High antifeedant activity of isovellerol, a gamma-hydroxy-aldehyde ses quiterpene of marasmane skeleton prompted us to synthesize the same ty pe of compounds with the isolactarane skeleton, and to check their ant ifeedant activity. LiAlH4 reduction of isolactarorufin gave the desire d compound, besides the tetraol (a compound with open lactone ring). E xtensive spectroscopic investigation (including X-ray) indicated that the desired gamma-hydroxy-aldehyde in chloroform solution existed in t he cyclic (lactol) form. Antifeedant activities of both compounds agai nst the storage pests were moderate.