Testosterone Undecanoate CAS No 5949-44-0

The number and position of double bonds in various natural steroid molecules, the type, number and position of substituted groups, the configuration between the substituted group and the annular nucleus, and the configuration of ring and ring are different. The six carbon rings A, B, and C in the natural steroid molecule are "chair-type" conformation (cyclohexane structure), which is the most stable conformation (the only exception is that a ring within the estrogen molecule is a planar conformation of the aromatic ring).