Diastereomerically enriched analogues of the water-soluble phosphine PTA: synthesis of phenyl(1,3,5-triaza-7-phosphatricyclo [[3.3.1.1.sup.3,7]]dec-6-yl)methanol (PZA) and the sulfide PZA(S) and X-ray crystal structures of the oxide PZA(O) and [Cp*Ir[Cl.sub.2](PZA)]

A diastereomerically enriched analogue of 1,3,5-triaza-7-phosphaadamantane (PTA) are obtained by reaction of PTA lithium salt with benzaldehyde. The corresponding sulfide [PZA(S)] and crystal structure of oxide [PZA(O)] are synthesized together with an iridium complex.