Showing structure for [3aR-(3aalpha,4aalpha,8beta,8abeta,9abeta)]-2,3,3a,4,4a,7,8,8a,9,9a-Decahydro-5,8a-dimethyl-3-methylene-2-oxonaphtho[2,3-b]furan-8-yl ester 2-methylpropanoic acid