K. Narkunan et al., Synthetic approach toward sesquiterpene lactones via intramolecular allylation of a tungsten-pi-allyl compound, SYNLETT, (9), 2000, pp. 1300-1302
A facile and stereocontrolled synthesis of a tricyclic alpha -methylene but
yrolactone is achieved smoothly via intramolecular allylation of an allyl-t
ungsten complex with its tethered aldehyde.