Total synthesis of vernolepin—I

The key intermediate (9) for the total synthesis of antitumor sesquiterpene vernolepin (1) was prepared in seventeen steps from 2,5-dihydroanisyl alcohol. Intramolecular Michael addition (7→ 8) afforded the cis-2-oxadecalone system, which was stereospecifically converted to 9 by using the enolization character of 8.