Synthesis of the Lichen Metabolite (+)-Bourgeanic Acid and Conformational Analysis of Its Dilactone

Article abstract of DOI:10.1021/jo00311a009

An enantiospecific synthesis of the depside (+)-bourgeanic acid via (-)-hemibourgeanic acid defines the letter as (2S,3S,4R,6R)-3-hydroxy-2,4,6-trimethyloctanoic acid and the former as its self-esterification product.Conformational analysis of the dilactone derived from bourgeanic acid shows that the eight-membered ring adopts a crown conformation with C2 symmetry and all substituents in equatorial orientation.