Synonyms: 2(1H)-Pyrimidinone,4-amino-1-[2-(hydroxymethyl)-1,3-oxathiolan-5-yl]-, S-oxide, [2R-(2a,3a,5a)]-; 1,3-Oxathiolane, 2(1H)-pyrimidinone deriv.; 2(1H)-Pyrimidinone,4-amino-1-[2-(hydroxymethyl)-3-oxido-1,3-oxathiolan-5-yl]-, [2R-(2a,3a,5a)]-; GI 138868X