(4aS,4bR,5S,6aS,6bS,9aR,10aS,10bS)-6b-(chloroacetyl)-4b-fluoro-5-hydroxy-4a,6a,8,8-tetramethyl-3,4,4a,4b,5,6,6a,6b,9a,10,10a,10b,11,12-tetradecahydro-2H-naphtho[2',1':4,5]indeno[1,2-d][1,3]dioxol-2-one