Acetic acid, 2-​[[(3aR,​4S,​6R,​6aS)​-​6-​aminotetrahydro-​2,​2-​dimethyl-​4H-​cyclopenta-​1,​3-​dioxol-​4-​yl]​oxy]​-​, ethyl ester, ethanedioate (1:1)