[3aS-(3aα,4β,5α,6α,8β,9α,9aβ,10S*)]-[(2-Amino-1,1-dimethylethyl)thio]acetic Acid , 6-Ethenyldecahydro-5-hydroxy-4,6,9,10-tetramethyl-1-oxo-3a,9-propano-3aH-cyclopentacycloocten-8-yl Ester; 3a,9-Propano-3aH-cyclopentacyclooctene Acetic Acid Derivative