Convergent Total Synthesis of Exochelin 772SM.

A convergent total synthesis of the natural mycobacterial iron chelator desferri-exochelin 772SM (D-EXO) is described. The synthetic procedure proceeds in 11 steps in the longest linear sequence, with an overall yield of 8.6%. The described procedure uses cheap starting materials and requires a limited number of chromatographic purifications. The concise strategy divides the exochelin into five key building blocks, allowing easy alternation of each single building block. Herein, the presented synthetic strategy is well suited to facilitate the synthesis of analogues and medicinal chemistry development efforts in a time- and resource-efficient manner.