| abstract |
A compound represented by the following formula [I] ornan optically active substance or a salt thereof.n n(In the formula, a bond shown by a dotted line in the five-memberednring means that said five-membered ring may be any ofna cyclopentene ring having a double bond and a cyclopentane ringnwhere said bond is saturated and, in the case of a cyclopentenenring, X is OH, Y is =O and Z is H while, in the case of ancyclopentane ring, X is =O, Y is OH and Z is OH. R is a residuenafter removal of an SH group from the SH-containing compound.) |