4-Amino-3-hydroxy-2,4-(disubstituted)pentanoic acids of the formula: ##STR1## useful as intermediates in preparing antibacterial compounds, are synthesized enantiospecifically by acylation of a chiral enolate with an optically active acylating agent. The resulting product is reduced stereospecifically to afford a protected form of the desired product, which contains three adjacent asymmetric centers of known configuration. The synthesis may be illustrated as follows: ##STR2##
式为:##STR1## 的4-
氨基-3-羟基-2,4-(二取代)
戊酸是制备抗菌化合物的中间体,通过用手性烯醇酸化剂酰化手性烯醇酯的方法对其进行对映选择性合成。所得产物经立体选择性还原,得到所需产物的保护形式,其中包含三个已知构型的相邻不对称中心。合成可如下所示:##STR2##