The asymmetric cross-aldol reaction of simple ketones (acetone, cyclohexanone) with isatin derivatives in the presence of crude extract from earthworms as green and effective biocatalyst proceeds easily in MeCN/H₂O (1:1) as solvent to afford 3-hydroxy-2-oxindoles derivatives. Ten compounds were synthesized in high yields (62–88%) and moderate ee (29–42%). Structure of the synthesized compounds has been characterized on the basis of NMR spectra and CHN analysis. The ee of the obtained compounds was determined by chiral phase HPLC analysis.

中文翻译：

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worm提取物催化的高效催化生物素与酮的不对称交叉羟醛反应

在earth粗提物的存在下，简单的酮（丙酮，环己酮）与靛红衍生物的不对称交叉醛醇缩合反应作为绿色有效的生物催化剂，在以MeCN / H ₂ O（1：1）为溶剂的溶剂中容易进行，得到3-羟基-2-氧吲哚衍生物。十种化合物的合成产率高（62–88％）和中等ee（29–42％）。合成的化合物的结构已根据NMR光谱和CHN分析进行了表征。通过手性HPLC分析确定所获得的化合物的ee。