Diastereoselective Formation of Methylene-Bridged Glycoluril Dimers.

The acid-catalyzed formation of methylene-bridged glycoluril dimers yields the C(2)(v)()-diastereomer selectively. Product resubmission experiments establish that the selectivity is the result of thermodynamic control. A modified synthetic route is presented that allows for the preparation of unsymmetrically substituted dimers. We present the X-ray crystal structures of both diastereomers. This class of compounds is useful for studies of self-assembly in aqueous solution.