Remarkably Facile Ring‐Size Control in Macrocyclization: Synthesis of Hemicucurbit[6]uril and Hemicucurbit[12]uril

Abstract

A question of concentration: The condensation of ethyleneurea and formaldehyde can be controlled perfectly by the HCl concentration to provide either a hemicucurbit[6]uril 1, which functions as a host, or hemicucurbit[12]uril 2, which acts as a gelating agent, in yields of 94 and 93 %, respectively. Supporting information for this article is available on the WWW under http://www.wiley-vch.de/contents/jc_2002/2004/z460764_s.pdf or from the author. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.