Gold(I) as an Artificial Cyclase: Short Stereodivergent Syntheses of (-)-Epiglobulol and (-)-4β,7α- and (-)-4α,7α-Aromadendranediols

Three natural aromadendrane sesquiterpenes, (−)-epiglobulol, (−)-4β,7α-aromadendranediol, and (−)-4α,7α-aromadendranediol, have been synthesized in only seven steps in 12, 15, and 17 % overall yields, respectively, from (E,E)-farnesol by a stereodivergent gold(I)-catalyzed cascade reaction which forms the tricyclic aromadendrane core in a single step. These are the shortest total syntheses of these natural compounds.