Lasidiol

Leaf cutter ants, abundant from Texas to Argentina are polyphagous herbivores, but will not attack several plants. The ant, Atta cephalotes, for example, does not feed on Lasianthaea fruticosa (Asteraceae). The active repellent substance has been demonstrated to be lasidiol angelate (8p. 

Leaf cutter ants, abundant from Texas to Argentina, are polyphagous herbivores, but will not attack several plants. The ant, Atta cephalotes, for example, does not feed on Lasi-anthaea fruticosa (Asteraceae). The active repellent substance is lasidiol angelate (51) (Wiemer and Ales, 1981). Three of four other inhibitory compounds to ant feeding, nerolidol (7), caryophyllene epoxide (52), kolavenol (a diter-pene), and caiyophyllene (not active), either produced dramatic effects on the ants or the fungus cultivated by the ants (Howard et al., 1988). 

Wiemer, D. F. and D. C. Ales, Lasidiol angelate Ant repellent sesquiterpenoid from Lasianthaea fruticosa, J. Org. Chem., 46, 5449-5450 (1981). 

The natural product lasidiol 217 (Figure 19.23) is a member of the daucane class of sesquiterpenes, which contain a bicyclo[5.3.0]decane ring system [106]. While studying the utility of intramolecular [4-1-3] cycloaddition reactions, Kreisehneier and Fohlisch accomplished a total synthesis of racemic lasidiol [107]. 

In any case, cycloadduct 221a contained the appropriate relative stereochemical arrangement of substituents found in lasidiol and as such was carried forward (Scheme 19.48). Stereoselective reduction of 221a with lithium aluminum hydride and hydrogenation of the olefin afforded bromohy-drin 223. Treatment of 223 with n-butyllithium (deprotonation) followed by sodium naphthalenide resulted in reductive elimination with concomitant ring opening of the ether bridge to afford lasidiol 217. 

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