An iterative, facile stereoselective synthesis of C1-C11 fragment of borrelidin via enzymatic desymmetrization strategy

Abstract

A highly stereoselective and general method for the synthesis of the C1-C11 fragment of borrelidin has been achieved. The main feature of our synthetic route is enzymatic desymmetrization to create two methyl bearing chiral centres, use of Evans auxiliary to introduce two other methyl groups and creation of C3 stereocentre by regioselective opening of an epoxide arising from Sharpless epoxidation protocol. The synthesis of the C1-C11 subunit was achieved in gram scale by a linear synthetic sequence in an overall yield of 18.4%.