Synthesis of tetrahydrofuran-based natural products and their carba analogs via stereoselective enzyme mediated Baeyer–Villiger oxidation

Abstract

In this work we present efficient formal syntheses of several biologically interesting natural products (showdomycin, goniofufurone, trans-kumausyne) and their novel carba analogs by applying different Baeyer–Villiger monooxygenases. This strategy provides access to tetrahydrofuran-based natural products, C-nucleosides and both antipodes of the corresponding carba analogs in high optical purities (up to >95% ee) starting from simple achiral and commercially available building blocks (tetrabromoacetone, furan and cyclopentadiene). The striking key features of this chemo-enzymatic approach are the introduction of four stereogenic centers in as few as three reaction steps within a desymmetrization approach and the short-cut of several reaction sequences by the implementation of a biocatalytic step.