Abstract 1-Phenylthymine and the carbocyclic analog of thymidine were obtained in yields of 84-87% by cyclizing the appropriate 3-methoxy-2-methylacryloylureas in dilute sulfuric acid. High yields of 1-phenylthymine also resulted when the cyclization was carried out in trifluoroacetic acid, in acetic acid containing toluenesulfonic acid (TSA), or by fusion of the urea with a catalytic amount of TSA. In comparison, the typical aqueous-alkali catalyzed ...
![(+/-)-N-[[(1α,3β,4α)-3-hydroxy-4-(hydroxymethyl)cyclopentyl]aminocarbonyl]-3-methoxy-2-methyl-2-propenamide Structure](https://image.chemsrc.com/caspic/068/61809-19-6.png)
