2,2'-Anhydro(1-.beta.-D-arabinofuranosyl)uracil 2,2'-Anhydrouridine 2,2'-O-Cyclouridine 3736-77-4 6H-Furo[2',3':4,5]oxazolo[3,2-a]pyrimidin-6-one, 2,3,3a,9a-tetrahydro-3-hydroxy-2-(hydroxymethyl)-, [2R-(2.alpha.,3.beta.,3a.beta.,9a.beta.)]- 6H-Furo[2',3':4,5]oxazolo[3,2-a]pyrimidin-6-one, 2,3,3a,9a-tetrahydro-3-hydroxy-2-(hydroxymethyl)-, stereoisomer Cyclouridine NSC157148 O2,2'-Cyclouridine