Studies on the synthesis of 4,5-dihydroxyimidazolidin-2-ones (-thiones) based on the condensation of ureas or thioureas with glyoxal or 1,2-dioxo-1,2-diphenylethane showed high diastereoselectivity in the formation of racemates (trans-diastereomers) of 4,5-dihydroxyimidazolidin-2-ones (-thiones) and meso-forms (cis-diastereomers) of 4,5-dihydroxy-4,5-diphenyl-1,3-dialkylimidazolidine-2-thiones; plausible mechanisms of their formation were suggested. X-ray diffraction studies confirmed structures of diastereomers for separate examples of racemates and meso-forms of 4,5-dihydroxyimidazolidin-2-ones (-thiones).
基于
脲类或
硫脲类与
乙二醛或 1,2-二氧代-1.2-二苯基
乙烷缩合合成 4,5-二羟基
咪唑烷-2-酮(-thiones)的研究表明,4,5-二羟基
咪唑烷-2-酮(-thiones)的外消旋体(反式-非对映异构体)的形成具有高度非对映选择性、2-二苯基
乙烷缩合而成的 4,5-二羟基
咪唑烷-2-酮(-
硫酮)的外消旋体(反式-非对映异构体)和 4,5-二羟基-4,5
-二苯基-1,3-二烷基
咪唑烷-2-
硫酮的中间体(顺式-非对映异构体)的非对映选择性很高;提出了它们的合理形成机制。X 射线衍射研究证实了 4,5-二羟基
咪唑烷-2-酮(-
硫酮)外消旋体和中消旋体的非对映异构体结构。