Theoretical values can not only assign the hydrogen chemical shifts in seven-membered ring, but also explain diastereotopic effect of hydrogen in methylene caused by S=S bond.

• 理论值一方面可以对七元环上四个氢的化学位移做出指认，另一方面也对S=S键引起的亚甲基上氢的非对映异位给出解释。