The macrocycle shown below was recently published in Tetrahedron Letters (Volume 51, Issue 10, 10 March 2010, Pages 1361-1363 ) and this time they have a single crystal X-ray structure to back it up. Despite what you might think at first, the ring is closed in very good yield (44-93%) since it exploits the preferred amide-confromation of the secondary aryl benzoic acid amide. This might make an interesting template for drug design.
