英文别名2-[2-(3,4-Dihydro-6-methoxynaphthalen-1(2H)-ylidene)ethyl]-2-ethyl-1,3-cyclopentanedione; 2-ethyl-2-[(2Z)-2-(6-methoxy-3,4-dihydro-2H-naphthalen-1-ylidene)ethyl]cyclopentane-1,3-dione; 2-[2-(3,4-dihydro-6-methoxy-1(2H)-naphthalenylidene)ethyl]-2-ethyl-1,3-cyclopentanedione; Levonorgestrel Impurity 2; 3-methoxy-13-ethyl-8,14-seco-1,3,5(10),9(11)-estratetraen-14,17-dione; (+/-)-3-Methoxy-13β-ethyl-8(14)-seco-1,3,5(10),9(11)-gonatetraene-14,17-dion; 2-[2-(3,4-Dihydro-6-methoxy-1(2H)-naphthylidene)-ethyl]-2-ethylcyclopentane-1,3-dione; dl-3-Methoxy-13-ethyl-8,14-seco-gona-1,3,5(10),9-tetraen-14,17-dion; 2-[2-(3,4-2H-6-METHOXY-1(2H)-NAPHTHYLIDENE)ETHYL]-2-ETHYLCYCLOPENTANE-1,3-DIONE 
