Terpenoid chirons: Preparation and transformations of 2-hydroxy-1,1,4a(R),6-tetramethyl-trans-Δ5,6-octalin
摘要:
Octalins 4 and 5 are prepared conveniently in 3 steps from commercial 18beta-glycyrrhetinic acid and converted to a variety of functionalized trans-AB ring chirons.
A full account on the first totalsynthesis of a chroman meroterpenoid, (-)-phomoarcherin C, has been described. Key synthetic transformations include phenyl boronic acid-mediated 6π-electrocyclization reaction, a stereospecific hydrogenation driven by thermodynamic conformational stability of the product, and regioselective formylation. The strategy employed is considerably short, is atom-economical