4′‐tert‐Alkylbenzo[15]Crown‐5‐Ether. Syntheses and Complexes with Potassium ThiocyanateThe title compounds4are synthesized either by alkylation of pyrocatechole1in 4‐position and followed by ring closure with 1,11‐dichloro‐3,6,9‐trioxaundecane or by alkylation of benzo[15]‐crown‐53. In most cases the way first mentioned gives better results. Analytical samples of the alkylated benzo[15]crown‐5 ethers4are obtained through complexing with KSCN.Physical data and1H‐n.m.r.‐spectra of 5 new pyrocatecholes2and 6 new benzo[