Total Syntheses of the\nTropolone-Containing Sesquiterpene\nOlaximbriside A and Its Decarbonylated Counterpart Olaximbriside B

The racemic modification of the α-tropolone-containing\nsesquiterpene\nolaximbriside A [viz. (±)-<b>4</b>)] has been prepared\nover 12 steps from the readily accessible decalin derivative <b>12</b>. The last two of these steps involve a fully regiocontrolled\nsubstitution reaction of bromotropone <b>24</b>. The aromatization\nof a stereoisomeric and co-produced form of compound <b>12</b> has provided (±)-olaximbriside B [(±)-<b>5</b>)].