Stereochemical behavior of oxirane and bioxirane in their polymerizations initiated with an organozinc complex having chair-type structure

A well-defined organozinc complex, MeOCH₂CH(Me)OZn-OCH(Me)CH₂OMe]₂EtZnOCH(Me)CH₂OMe]₂ (Zn-MP]_{2, 2}), is a very unique and versatile initiator for polymerization of oxirane and bioxirane. Zn-MP]_{2, 2} induced “pure” isospecific polymerization of tert-butylethylene oxide. The two to two complex, however, became a syndiospecific initiator for cis-α, β-disubstituted oxirane. Regioselective nature of ZnMP]_{2, 2} complex against bioxirane made it possible to prepare a soluble polyether having pendant oxirane rings.