(S)-3-Isopropyl-5-[(S)-1-((1aR,3aR,3bS,5aS,6R,8aS,8bS,10R,10aR)-10-methoxy-3a,5a-dimethyl-hexadecahydro-cyclopenta[a]cyclopropa[2,3]cyclopenta[1,2-f]naphthalen-6-yl)-ethyl]-4,5-dihydro-isoxazole

(20S,5'ξ)-20-(3'-isopropylisoxazoline-5'-yl)-6β-methoxy-3α,5-cyclo-5α-pregnane