The synthesis of a new bis (phosphotriester) macrobicyclic polyether cryptand, O= P [O (CH2) 20-(CH&. O (CH2) 20] 3P= O (9)) called phosphocrypt, and its acyclic tripodal precursor O= P [O (CH2) 20-(CHZ) ZO (CHZ) ZOHI~(8) are described. The new cryptand 9 was synthesized by condensation of 8 and phosphoryl chloride which were simultaneously added under high dilution conditions in the presence of pyridine. The highest yield of 9 ( ...