A series of acid-labile, optically pure ε-substituted δ-ketal-β-hydroxy esters were obtained by a Ru-SunPhos catalyzed asymmetric hydrogenation of the corresponding ε-substituted δ-ketal-β-keto esters. CaCO3 played a dual role in the hydrogenation reactionâremoving the acid generated during the formation of the catalyst and maintaining the activity of the catalyst.
通过Ru-SunPhos催化不对称氢化相应的ε-取代δ-酮
缩酮-β-
酮酯,获得了一系列酸不稳定的、光学纯的ε-取代δ-酮
缩酮-β-羟基酯。在氢化反应中,CaCO3发挥了双重作用——清除催化剂形成过程中产生的酸,并保持催化剂的活性。