A series of mixed tetraethers of calix [4] arene and p-tert-butylcalix [4] arene in which two distal substituents are methyl and the other two 1-alkenyl groups with 3, 4 and 5 carbon atom chains have been prepared by two routes which differ in the order in which the groups (methyl or alkenyl) were introduced. The ethers of p-tert-butylcalix [4] arene were isolated as a mixture of cone (minor) and partial cone (major) conformations in dynamic equilibrium. ...