Synonyms: 2,5-Methano-5H,9H-pyrimido[2,1-b][1,5,3]dioxazepin-9-one,2,3-dihydro-8-methyl-3-[(triphenylmethoxy)methyl]-, [2R-(2a,3b,5a)]-;2,5-Methano-5H,9H-pyrimido[2,1-b][1,5,3]dioxazepin-9-one,2,3-dihydro-8-methyl-3-[(trityloxy)methyl]- (7CI,8CI);Thymine,2,3'-anhydro-1-(2-deoxy-5-O-trityl-b-D-threo-pentofuranosyl)- (8CI);