M. ANTEUNIS, M. VERZELE and G. DACREMONT ... A series of tri-acylated and tri-arylated tris(hydroxymethy1)phosphine oxide derivatives was prepared either from tris-(hydroxymethy1)phosphine oxide or from tris-(iodomethy1)phosphine oxide. ... The following two methods are described in the literature for the preparation of esters of tris-(hydroxyrnethyl) phosphine exido (1' 2). Specific examples are :