From the CD curves of compounds 1-3(Fig. 1 in Chinese Text;compound 4 being transparent),it is seen that the positive absorption drift of 1 and 3 may be attributed to the peroxidic linkage, which is twisted clockwise as shown by molecular models. However, more eganiples will be needed to vindicate the proposed correspondence between the handedness of the torsion angle of the perogidic linkage and the sign of tho CD background.