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.

Concise approach to the carbocyclic core of the naturally occurring sphingomyelinase inhibitor scyphostatin.

A flexible strategy toward the carbocyclic core of the naturally occurring sphingomyelinase inhibitor scyphostatin, from the readily available Diels-Alder adducts of cyclopentadiene and 2-allyl-p-benzoquinone, has been devised. This approach leverages the stereochemical predisposition of the norbornyl-fused scaffolds to generate the desired stereochemical pattern and leads to a concise synthesis of the epoxycyclohexenoid core of scyphostatin with a manipulable allyl side arm.