Multiple reductive cleavage of calixarene diethyl phosphate esters: a route to [1 n ]metacyclophanes

Abstract

The OH groups of p-t-butylcalix[n]arene (n= 4 and 8) were converted into diethyl phosphate esters and reductively cleaved by treatment with K/NH3 to yield tetra-p-t-butyl[14]- and octa-p-t-butyl[18]metacyclophanes (4) and (7).