Synonyms: Naphth[2',1':4,5]indeno[7,1-bc]furan,2'H,5'H-pregnano[12,13,17-bc]furan deriv.;Naphth[2',1':4,5]indeno[7,1-bc]furan, 2a-ethyloctadecahydro-5b,11c-dimethyl-,[2aR-(2aa,5ab,5ba,11aa,11bb,11ca)]-; [2aR-(2aa,5ab,5ba,11aa,11bb,11ca)]-2a-Ethyloctadecahydro-5b,11c-dimethylnaphth[2',1':4,5]indeno[7,1-bc]furan