The HWE (Horner-Wadsworth-Emmons) reaction performed on the easily obtainable 5, 17- diformylcalix [4] arenes (cone) with arylmethyl phosphorus ylides yielded 5, 17-distyryl-25, 26, 27, 28-tetrapropoxycalix [4] arenes (cone) in high yield and purely in the E/E configuration. Compounds 2-5 were prepared this way containing bromine. Subsequent bromine-lithium exchange and reaction with trimethoxyborane yielded the dihydroxyboryl- ...
