2,4(1H,3H)-Pyrimidinedione, 1-[2-deoxy-3-O-(methylsulfonyl)-.beta.-D-threo-pentofuranosyl]-5-methyl- 3'-Mesyl-2'-dT 3'-Mesyl-thymidine B-D-threo 94919-65-0 AIDS-000931 AIDS000931