Synthesis and investigation of dynamic NMR behavior of mono derivative of Calix-quinone

Calixarenes have been subjected to a large number of chemical modifications over the last two decades. Calix-quinones are interest as complexing agents with redox or charge transfer properties and as synthetic key material for the preparation of functionalized Calixarenes and Calix-dimers [1]. In this work, Calix [4]-tripropoxy-monoquinone (4) was prepared from p-tert butylcalix[4]aren (2) by the selective trialkylation followed by oxidizing agents, respectively [2]. The Quinone derivative has been characterized by 1H-NMR, 13C-NMR and MS as well. The conformational behaviour of Calix [4]-tripropoxy-monoquinone was studied by low temperature 1H-NMR. This study shows the bridge protons can be affected by temperature (Scheme