4-Amino-5-fluoro-1-[(2R,3S,5S)-2-(hydroxymethyl)-3-oxido-1,3-oxathiolan-5-yl]-2(1H)-pyrimidinone ; 4-amino-5-fluoro-1-((2R,3S,5S)-2-(hydroxymethyl)-3-oxido-1,3-oxathiolan-5-yl)pyrimidin-2(1H)-one ; Emtricitabine S-Sulfoxide ; (S)-Emtricitabine sulfoxide, (S)-Emtricitabine 3'-oxide;Emtricitabine S-sulfoxide (USP);Emtricitabine S-sulfoxide;2(1H)-Pyrimidinone, 4-amino-5-fluoro-1-[(2R,3S,5S)-2-(hydroxymethyl)-3-oxido-1,3-oxathiolan-5-yl];4-Amino-5-fluoro-1-[(2R,3S,5S)-2-(hydroxymethyl)-3-oxido-1,3-oxathiolan-5-yl]-2(1H)-pyrimidinone