Oxidative Transformations of Guaia-1(10)-en-12,8-olides into Xanthanolides

Abstract

Dihydropsuedoivalin (1) was isolated from Stevia tomentosa, which, when treated with base, afforded epidihydropseudoivalin (2). The stereochemistry of 1 and 2 was established by crystallographic X-ray studies of the two derivatives of epidihydropseudoivalin. Treatment of 1 and 2 with Jones's reagent afforded the xanthanolides 3 and 4, respectively.

Natural sesquiterpenoids (1999)

“…379 The oxidative transformation of guaia-1(10)-en-12,8-olides into xanthanolides has been reported. 380 Two new sesquiterpene lactone glycosides with a carabrane skeleton 410 and 411 have been found in the flowers of Arnica longifolia. 381 Six new pseudoguaianolides 412-417 have been obtained from the aerial parts of Parthenium hysterophorus.…”