Showing structure for (4r,4as,5r,6s,8ar,9as)-4-hydroxy-9a-methoxy-3,4a,5-trimethyl-2-oxo-4h,5h,6h,7h,8h,8ah,9h-naphtho[2,3-b]furan-6-yl 2-methylbut-2-enoate