Mechanistic studies on gold mediated cross-coupling reactions and total synthesis of (_+ )-epiglobulol

Identifier:  TDX:1261

Handle: https://hdl.handle.net/20.500.11797/TDX1261

Authors:  Livendahl, Madeleine

Abstract:
1,6-enynes,bearing alcohol oretherfunctionalgroups,activatedbycationicgold(I) complexes can be trappedintra- orintermolecularlyfromalkenesorbenzylethers. Thisstereospecificreactiongivestricyclicproductsrelatedtosesquiterpenes 4-epiglobulol and 4-aromadendrene. Theracemicsynthesis of 4-epiglobulol startedwithcommerciallyavailablegeranylacetone. Wehavecompletedthe total synthesis of natural product(±)-epiglobulol in 5 stepswith a total overallyield of 16%. Wehaveinvestigatedthe C-C couplingmediatedbygold, showingthat in thecatalyticcyclethefrustratedstepistheoxidativeaddition. Wedesigned 4 new ligandsthatintramolecularlyhavethecapacitytooxidativelyaddforming 5 or 6 memberedcycles. However, none of theformedcomplexesunderwentoxidativeadditionwiththeligands. Wehavecompletedthe total synthesis of natural product (-)-agrimonol in 8 stepswith a total overallyield of 1.3%.with a selectivity of 3:1 startingfromcommerciallyavailable 3,5-dimethoxy-phenyl bromide.