The synthesis of chiral dimethyl substituted macrocyclic polyether‐diester ligands

A new series of chiral macrocyclic polyether‐diester ligands has been prepared from four chiral dimethyl substituted tetraethylene glycols (15a,b,16,17) and 2,6‐pyridinedicarbonyl chloride (products 5a‐7), diglycolyl chloride (products 8–10), thiadiglycolyl chloride (product 11), 2,5‐furandicarbonyl chloride (product 12), 4‐chloro‐2,6‐pyridinedicarbonyl chloride (product 13), and 4‐methoxy‐2,6‐pyridinedicarbonyl chloride (product 14). The chiral dimethyl substituted tetraethylene glycols (15a‐17) were prepared from ethyl (S)‐lactate.