Asymmetric synthesis of 3β-angeloyloxy-4β-hydroxyeudesman-8-one, purported sesquiterpene from Pluchea quitoc †

Eudesmane sesquiterpenoids from the Asteraceae family

“…176 The hydroxylation of sesquiterpenes by enzymes from chicory roots has been investigated. 177 3b-Angeloyloxy-4b-hydroxyeudesman-8one 206 has been synthesised by an unambiguous route, 178 but its spectroscopic data was different from that of the natural product, to which this structure had been assigned. 101, 179 An efficient and stereoselective synthesis of (+)-a-cyperone has been devised, 180 and the eudesmanolide artemsin has been used as a starting material in the preparation of 9-oxy-functionalised natural eudesmanes.…”

Efficient, Highly Enantioselective Synthesis of Selina-1,3,7(11)-trien-8-one, a Major Component of the Essential Oil of Eugenia uniflora

“…Dextrorotatory octalone 2a (Scheme ), of known absolute stereochemistry, was readily secured as previously described , and then recrystallized to afford highly enantioenriched starting material (≥98% enantiomer excess). This enone was next converted in quantitative yield into its tosylhydrazone derivative 2b , which underwent double-bond translocation with concomitant carbonyl reduction under the “alkene walk” procedure to give, in a highly stereoselective manner, the desired cis-fused octalone derivative 3a (79% yield).…”