6 -Eudesmanolides

Oltra and Cuerva have reported a unified strategy for the synthesis of the eudesmanolides that relies on the collidine-chlorotrimethylsilane reagent... 

In summary, feverfew appears to be a source of a range of sesquiterpene lactones of three different types germacranolides, eudesmanolides and guaianolides. 

An investigation of the constituents of Mexican species of the genus Eupatorium has resulted in the isolation of sesquiterpenoids belonging to the eudesmane (294a and b), eudesmanolide (295a and b), cadinane (296), and guanolide (297) groups. 

Vol. 5, p. 76). Related studies have shown that the butenolide derivative (319) can be used as an annulating agent in the construction of linear tricyclic y-lactones [cf. (322) and (323)] and it is expected that this methodology may be applied to the synthesis of naturally occurring eudesmanolides." ... 

A sultone analog of 107 (4-Me(eq)) instead of 3-Me(eq))] is the key intermediate of the first enantioselective total synthesis of the antileukemic l,10-ji ( ti-eudesmanolides, (—)-eriolanin and (—)-eriolangin <2001EJ03669, 2006EJ01144>. 

Oksiiz, S. and Topcu, G., A eudesmanolide and other constituents from Inula graveolens. Phytochemistry, 31, 195, 1992. 

Three research groups have developed synthetic routes which provide the basic A/B ring system of the plant-growth-inhibitory seco-eudesmanolides (elemanes) vernolepin (230), vernodalin (231),106 and vernomenin (232). In one approach107... 

Eudesmanolide sesquiterpene lactones (G6 G6 C40L) include a variety of variously cytotoxic compounds. The antifeedants alantolactone and isoalantolactone (helenin being a mixture of the two) (C6 ] C5 C40L=CH2) are antimicrobial. The pro-apoptotic activity of these compounds may derive from the reactivity of the a-methylene-y-butyrolactone ring... 

Frullanolide (eudesmanolide sesquiterpene lactone) 18(3-Glycyrrhetinic acid... 

Alantolactone (eudesmanolide sesquiterpene lactone) Inula helenium I. spp. (Asteraceae) Insect antifeedant... 

Euonymus europaeus although the exact positions of the various esters are not yet known. New eudesmanolides are listed in Table... 

This reaction has been used in a total synthesis of the eudesmanolide frullanolide (4), equation (II) . 

Transannular cyclizations generally contribute to the enhancement of molecular rigidity and structural complexity, two properties often associated with biological activity of small molecules [114]. In this scenario, we found that the Cp2TiCl-mediated transannular cychzation of 1,10-epoxycostunolide, a homo chiral material accessible in (multi)gram quantities, provides a straightforward way for the enantiospecific synthesis of eudesmanolides such as (-i-)-reynosin (18) (Scheme 23) and (-i-)-3a-hydroxyreynosin [47]. 

In the synthesis of functionalized eudesmanolides only the product with a /i-onentated hydroxy group was found after oxidation of the selenide with peracetic acid37. 

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