Synthesis of the Polyoxygenated Cyclohexanoid Core of Bioactive Glycosides Xylosmin and Flacourtosides E and F

A flexible
synthesis of the carbocyclic core present in glycosides
xylosmin and flacourtosides E and F, natural products exhibiting antimalarial
and antiarboviral activities, has been accomplished. Our approach
emanates from the Diels–Alder adduct of cyclopentadiene and
MOM-protected 2-hydroxymethyl-p-benzoquinone and
takes advantage of the stereochemical propensity of the norbornyl-fused
scaffolds to generate the dense oxy-functionalization pattern with
stereocontrol, enroute to a racemic synthesis of the carbocyclic core
present in the aforementioned bioactive materials. This effort augurs
well for exploring chemical diversity space around their scaffold.