Showing structure for [4aS-(4aalpha,5alpha,6beta,7alpha,8abeta)]- 6-(Acetyloxy)-4,4a,5,6,7,8,8a,9-octahydro-3,4a,5-trimethylnaphtho[2,3-b]furan-7-yl ester 3-methyl-2-butenoic acid