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.

• 指出了内消旋体消旋原因传统解释的不合理性。利用螺旋理论和稳定的交叉式构象，合理地解释了内消旋体消旋的原因。