Synonyms: 2,5-Methano-5H,9H-pyrimido[2,1-b][1,5,3]dioxazepin-9-one,2,3-dihydro-3-(hydroxymethyl)-8-methyl-, methanesulfonate (7CI);2,5-Methano-5H,9H-pyrimido[2,1-b][1,5,3]dioxazepin-9-one,2,3-dihydro-3-(hydroxymethyl)-8-methyl-, methanesulfonate (ester) (8CI);2,5-Methano-5H,9H-pyrimido[2,1-b][1,5,3]dioxazepin-9-one,2,3-dihydro-8-methyl-3-[[(methylsulfonyl)oxy]methyl]-, [2R-(2a,3b,5a)]-; Thymine, 2,3'-anhydro-1-(2-deoxy-b-D-threo-pentofuranosyl)-, 5'-methanesulfonate;5'-O-Methanesulfonyl-2'-deoxy-2,3'-anhydrothymidine