Department of Applied Chemistry and Life Science, Toyohashi University of Technology, 1-1 Hibarigaoka, Tempaku-cho, Toyohashi 441-8580, Japan.
Molecules. 2020 Aug 27;25(17):3902. doi: 10.3390/molecules25173902.
Chiral tertiary α-hydroxyketones were synthesized with high enantiopurity by asymmetric decarboxylative chlorination and subsequent nucleophilic substitution. We recently reported the asymmetric decarboxylative chlorination of β-ketocarboxylic acids in the presence of a chiral primary amine catalyst to obtain α-chloroketones with high enantiopurity. Here, we found that nucleophilic substitution of the resulting α-chloroketones with tetrabutylammonium hydroxide yielded the corresponding α-hydroxyketones without loss of enantiopurity. The reaction proceeded smoothly even at a tertiary carbon. The proposed method would be useful for the preparation of chiral tertiary alcohols.
手性叔醇 α-羟基酮可通过不对称脱羧氯化和随后的亲核取代反应以高对映纯度合成。我们最近报道了在手性伯胺催化剂的存在下，β-酮羧酸的不对称脱羧氯化反应，以获得高对映纯度的α-氯代酮。在这里，我们发现，用四丁基氢氧化铵对得到的α-氯代酮进行亲核取代反应，可以得到相应的α-羟基酮，而对映纯度没有损失。即使在叔碳上，反应也能顺利进行。该方法将有助于制备手性叔醇。
