Phosphorotropic rearrangement in synthesis of asymmetrically-substituted calix[4]arenes
Abstract
Monosodium derivatives of 1,3-bis(diethoxyphosphoryl)-calix[4]arenes undergo O,O-phosphorotropic rearrangement into corresponding 1,2-bis(diethoxyphosphoryl)calix[4]arenes which are useful reagents in the synthesis of asymmetrically substituted calix[4]arenes with AABH-type substitution of the lower rim.