2-Butenoic acid, 4-(((5alpha,6alpha)-17-(cyclopropylmethyl)-4,5-epoxy-3,14-dihydroxymorphinan-6-yl)amino)-4-oxo-, methyl ester, (E)- 83339-80-4 N-Methyl-alpha-funaltrexamine N-Methylfunaltrexamine