Synthesis of two 1,3‐2,4‐calix[4]bis‐crown ethers containing two 1,2‐phenylene and one pyridine or anisole units in each crown ether moiety

Syntheses of 1,3–2,4‐calix[4]bis‐crown ethers ( 1 and 2 ) fixed in the 1,3‐alternate conformation by 1,3‐ and 2,4‐bridges made of two modified polyether chains each containing two 1,2‐phenylene residues and one pyridine or anisyl unit are reported. The structures of compounds 1 and 2 were established by ¹H nmr, ¹³C nmr, hrms and elemental analyses.