An Approach to Molecular Baskets with Ester-Crown Handles from Diphenylglycoluril

A series of basket-shaped hosts with ester-crown handles have been synthesized by treating oligoethylene glycol bischloroacetates ClCH₂CO(OCH₂CH₂) _n OCOCH₂Cl, n = 1, 2, 3, 4] and 1,2-bis(hydroxyethoxy)benzene bischloroacetates with a diphenylglycoluril-based molecular clip, 1,3:4,6-bis(3,6-dihydroxy-1,2-xylylene)tetrahydro-3a,6a-diphenylimidazo5,5]imidazole-2,5(1H, 3H)-dione (1), in dimethyl sulfoxide using K₂CO₃ as a base in yields of 15, 35, 40, 38, and 20%. Their structures were identified by nuclear magnetic resonance and mass spectrum. The reaction conditions were also studied and optimized. Translated from Journal of Wuhan University (Natural Science Edition), 2005, 51(3) (in Chinese)