Gold(I) as an artificial cyclase: short stereodivergent syntheses of (-)-epiglobulol and (-)-4ß,7α- and (-)-4α,7α-aromadendranediols.

ABSTRACT

Three natural aromadendrane sesquiterpenes, (-)-epiglobulol, (-)-4ß,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.