Enantioselective Reaction of α-Lithiated Dithioacetals Using Chiral Bis(oxazoline)s: New Chiral Formyl Anion Equivalents
作者:Shuichi Nakamura、Yuji Ito、Libo Wang、Takeshi Toru
DOI:10.1021/jo035558e
日期:2004.3.1
The enantioselective reaction of various α-lithiated dithioacetals with aldehydes or a ketone in the presence of bis(oxazoline)s was examined. Among them, unsymmetrical dithioacetals were found to be the best choice for attaining high enantioselectivity. The reaction of lithiated tert-butylthio(2-pyridylthio)methane with aldehydes proceeded with good diastereoselectivity as well as with good enantioselectivity
在双(恶唑啉)存在下,考察了各种α-锂化的二硫缩醛与醛或酮的对映选择性反应。其中,发现不对称的二硫缩醛是获得高对映选择性的最佳选择。锂化的叔丁基硫代(2-吡啶硫基)甲烷与醛的反应以良好的非对映选择性以及良好的对映选择性进行。对映选择性反应显示为通过动态热力学拆分进行。氯化汞(II)使产物的二硫缩醛部分水解为2-羟基醛,将其直接还原为光学活性的1,2-二醇。