Methyl zizanoate

(3S)-2,3,4,5,6,7,8,8aα-Octahydro-7,7-dimethyl-8-methylene-1H-3aα,6α-methanoazulene-3α-carboxylic acid methyl ester

methyl [3S-(3alpha,3aalpha,6alpha,8aalpha)]-octahydro-7,7-dimethyl-8-methylene-1H-3a,6-methanoazulene-3-carboxylate