3-Des(1-ethylpropoxy)-3-(1-methylpropoxy) Oseltamivir;Oseltamivir EP Impurity F;Oseltamivir Phosphate impurity F (EP);(3R,4R,5S)-ethyl 4-acetamido-5-amino-3-(sec-butoxy)cyclohex-1-enecarboxylate;(3R,4R,5S)-4-(Acetylamino)-5-amino-3-(1-methylpropoxy)-1-cyclohexene-1-carboxylic acid ethyl ester;Oseltamivir Impurity F