The reaction of the dianion of methyl (R)-3-hydroxybutanoate with the N-silylimine generated from trimethylsilylpropynal afforded (3R,4S)-3-[(R)-1-hydroxyethyl]-4-trimethylsilylethynyl-2-azetidinone as the major product, of which the stereochemistry was assigned through its stereospecific conversion to the (+)-4-acetoxy derivative.
                                    (R)-3-羟基丁酸甲酯的双阴离子与由三甲基甲
硅烷基
丙炔醛生成的 N-甲
硅烷基
亚胺反应得到 (3R,4S)-3-[(R)-1-羟乙基]-4-三甲基甲
硅烷基
乙炔基-
2-氮杂环丁酮主要产物,其立体
化学通过其立体有择转化为 (+)-4-乙酰氧基衍
生物指定。