2-((2S,6aS,6bS,7aS,8aS,8bS,11aR,12aS,12bS)-2-fluoro-6a,8a,10,10-tetramethyl-4-oxo-1,2,4,6a,7a,8,8a,8b,11a,12,12a,12b-dodecahydronaphtho[2′,1′:4,5]oxireno[2′,3′:5,6]indeno[1,2-d][1,3]dioxol-8b-yl)-2-oxoethyl acetate