Epoxyimines, formed with epoxyaldehydes, react via cycloaddition with amino-protected glycyl halides to provide 3-protected-amino-4-(substituted oxiranyl)azetidinones. Chiral epoxyimines from chiral epoxyaldehydes induce high levels of asymmetric induction during the cycloaddition to provide substantially one diastereomer of the 3,4-disubstituted azetidinone. For example, the epoxyimine formed with (2R,3S)-2-formyl-3-phenyloxirane and 2,4-dimethoxybenzylamine is reacted with phthalimidoacetyl chloride to provide [3R,4R,4(2S,3S)]-1-(2,4-dimethoxybenzyl)-3-phthalimido-4-(3-phenyloxiran-2-yl)-2-azetidinone.
The epoxy-substituted azetidinones are useful intermediates for β-lactam antibiotic compounds.
环氧
亚胺与环氧醛形成的环氧
亚胺与
氨基保护的甘
氨酰卤发生环化反应,生成 3-
氨基保护的-4-(取代的
环氧乙烷基)氮杂
环丁酮。在环化反应过程中,来自手性环氧醛的手性环氧
亚胺会产生高
水平的不对称诱导,从而提供 3,4-二取代氮杂
环丁酮的非对映异构体。例如,用 (2R,3S)-2-甲酰基-3-苯基
环氧乙烷和 2,4-二甲氧基
苄胺形成的环氧
亚胺与邻苯二甲
酰亚胺基
乙酰氯反应,得到 [3R,4R,4(2S,3S)]-1-(2,4-二甲氧基苄基)-3-邻苯二甲
酰亚胺基-4-(3-苯基
环氧乙烷-2-基)-
2-氮杂环丁酮。
环氧取代的氮杂
环丁酮是β-内酰胺类抗生素化合物的有用中间体。