The first total synthesis of three (+)-podophyllic aldehydes was achieved in a highly enantiocontrolled manner. Key steps include the organocatalyzed highly enantioselective cyclopropanation and Lewis acid-mediated chiral transfer ring expansion with excellent level of stereoinduction. This method can alternatively provide (+)- and (−)-podophyllic aldehydes by switching the organocatalyst in the asymmetric cyclopropanation.
首次实现了三种(+)-
鬼臼毒素醛的完全合成,采用了高度对映控制的方式。关键步骤包括通过有机催化的高度对映选择性
环丙烷化和
路易斯酸介导的手性传递环扩张,具有出色的立体诱导
水平。通过在不对称
环丙烷化步骤中切换有机催化剂,此方法可以交替提供(+)-和(−)-
鬼臼毒素醛。