Scyphostatin

This account details the synthesis of two scyphostatin analogues exhibiting a reactive polar epoxycyclohexenone core and various amide side chains outfitted for late-stage chemical derivatization into the desirable lipophilic tails. Our efforts highlight a key ipso-dearomatization process and provide new insights regarding the incompatibility and orthogonal reactivity of scyphostatin's functional groups. We further showcase the utility of resorcinol derived 2,5-cyclohexadienones as synthetic platforms capable of participating in selective chemical reactivity, and we further demonstrate their potential for rapid elaboration into complex structural motifs.

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.

A concise synthesis of two scyphostatin analogues is achieved from readily available ortho-substituted phenols. Key features include an asymmetric and biomimetic hydroxylative phenol dearomatization (HPD) reaction promoted by a chiral salen-type bis(λ5-iodane) reagent, followed by an in situ regio- and diastereocontrolled epoxidation.