A Stereocontrolled Synthesis of the C11-C24 Fragment of InostamycinA via the Desymmetrization of Glycerols

A robust and reproducible route has been developed for the synthesis of the C11-C24 fragment of inostamycinA. Whilst the core scaffold of this compound was constructed via a series of addition reactions and an aldol condensation, the stereogenic centers were installed via a series of complex reactions involving a diastereoselective desymmetrization for the two quaternary carbons at C16 and C20, a crotylation for the carbons at C17 and C18, an aldol condensation for the carbons at C12 and C13, an allylation for the carbon at C21, and a chiral building block for the installation of the carbon at C14. All of these steps proceeded with high yield and stereoselectivity, and were also scalable.