Stereoselective synthesis of the C-21 to C-27 segment of rifamycin-S
Abstract
An efficient synthesis of the ansa chain of rifamycin-S corresponding to the C-21 to C-27 segment is described, starting from a bicyclic precursor endo,endo-2,4-dimethyl-8-oxabicyclo[3.2.1]oct-6-en-3-one.