For the reason why optical activity of mesomer is counteracted classical answer was not convincing.

出了内消旋体消旋原解释不合。

For the reason why optical activity of mesomer is counteracted classical answer was not convincing. By use of the helix theory and stable staggered conformation answer can be obtained.

出了内消旋体消旋原解释不合。利用螺旋论和稳定交叉式构象，合地解释了内消旋体消旋原。