Cone calix[il]arenes substituted at the lower rim by one to four -CH2P
(O)Ph-2 functionalities have been prepared in moderate to excellent yi
eld, either directly from p-tert-butylcalix[4]arene or piecewise from
calix[4]arenes containing easily removable protecting groups. The X-ra
y structure of a calix[4]arene-derived tris-(phosphine oxide) is prese
nted. (C) 1997 Elsevier Science S.A.