Milbemycin EP Impurity A

Chemical Name: (1′R,2R,4′S,5S,6R,8′R,10′E,13′R,14′E,16′E,20′R,21′R,24′S)-6-Ethyl-21′,24′-dihydroxy-5,11′,13′,22′-tetramethyl 3,4,5,6-tetrahydrospiro[pyran-2,6′-[3,7,19] trioxatetracyclo[15.6.1.14,8.020,24]pentacosa[10,14,16,22]tetraen]-2′-one