Calix[4]bis(spirodienone) as a versatile synthon for upper rim alkoxylation of calixarenes and synthesis of novel triazole-based biscalixarene by 'CuAAC' chemistry

The spiro rings of calix[4]bis(spirodienone) have been opened up using various bromofunctionalised alcohols employing a novel ipso nucleophilic substitution of tert-butyl groups by alkoxy groups. Additionally, a route has been paved towards the preparation of triazole-linked biscalixarene via the copper(I)-catalysed modern version of classical Huisgen 1,3-dipolar cycloaddition of alkynyl calixarene and azidocalixarene, derived from the above-mentioned bromo-substituted calixarene.