Digoxin Impurity I

(2R,3R,4S,6S)-6-(((2R,3S,4S,6S)-6-(((2R,3S,4S,6R)-6-(((3S,5R,8R,9S,10S,12R,13S,14S,17R)-12,14-dihydroxy-10,13-dimethyl-17-(5-oxo-2,5-dihydrofuran-3-yl)hexadecahydro-1H-cyclopenta[a]phenanthren-3-yl)oxy)-4-hydroxy-2-methyltetrahydro-2H-pyran-3-yl)oxy)-4-hydroxy-2-methyltetrahydro-2H-pyran-3-yl)oxy)-3-hydroxy-2-methyltetrahydro-2H-pyran-4-yl acetate