Racemic 4‐oxocyclopent‐2‐en‐1‐yl acetate was used in a short synthesis of nucleoside analogues with pyrimidine and purine heterobases. The protocol is based on a typical nucleophilic substitution process. Uracil, thymine, 6‐chloropurine, and some adenines gave the expected 4‐heterosubstituted products along with the isomeric 2‐heterosubstituted compounds as minor components. Samples of selected products were evaluated for their antiviral activity in a primary screening against a variety of viruses belonging to different classes. One of the compounds was found to be highly active against human papilloma virus (HPV).

4-Heterosubstituted Cyclopentenone Antiviral Compounds: Synthesis, Mechanism, and Antiviral Evaluation. -The title cyclopentenones are prepared by a typical nucleophilic substitution process of racemic oxocyclopentenyl acetate with uracil, thymine, 6-chloropurine, and some adenines. Some compounds are screened for their activity against a variety of viruses of different classes. Compound (IIIa) is found to be highly active against human papilloma virus (HPV). -(MANTIONE, D.; AIZPURU, O. O.; MEMEO, M. G.; BOVIO, B.; QUADRELLI*, P.; Eur. J. Org. Chem. 2016, 5, 983-991, http://dx.