Total Syntheses of the Tropolone-Containing Sesquiterpene Olaximbriside A and Its Decarbonylated Counterpart Olaximbriside B.

The racemic modification of the α-tropolone-containing sesquiterpene olaximbriside A [viz. (±)- 4 )] has been prepared over 12 steps from the readily accessible decalin derivative 12 . The last two of these steps involve a fully regiocontrolled substitution reaction of bromotropone 24 . The aromatization of a stereoisomeric and co-produced form of compound 12 has provided (±)-olaximbriside B [(±)- 5 )].