Synthesis of a calix[4]crown modified with germanium‐containing side chains

A germacalix‐crown, 25,27‐bis1‐(3‐trimethylgermylpropyl)oxy]calix4]arene‐crown‐6, 1,3‐alternate ( 1a ), and its carbon analog, 25,27‐bis‐1‐(4,4‐dimethylpentyl)oxy]calix4]arene‐crown‐6, 1,3‐alternate ( 1b ), were prepared and their structures were confirmed by elemental analysis and ¹H and ¹³C NMR spectroscopy. A cation transport test indicated that both compounds exhibited much the same cation transport ability, so that the role of the germanium moiety in capturing and transporting counteranions is not yet clear. Copyright © 2005 John Wiley & Sons, Ltd.