Selective transacylation reactions on 4-aryl-3,4-dihydropyrimidin-2-ones and nucleosides mediated by novel lipases*
Poonam1,‡, Ashok K. Prasad1, Chandrani Mukherjee1, Gaurav Shakya1, Gautam K. Meghwanshi2, Jesper Wengel3, Rajendra K. Saxena2, and Virinder S. Parmar1
1Bioorganic Laboratory, Department of Chemistry, University of Delhi, Delhi 110 007, India; 2Department of Microbiology, University of Delhi South Campus, Benito Juarez Road, New Delhi 110 021, India; 3Nucleic Acid Center, Department of Chemistry, University of Southern Denmark, Campusvej 55, DK‑5230 Odense M, Denmark
Abstract: Different (±)-4-(3/4-acetoxyaryl)-5-ethoxycarbonyl-6-methyl-3,4-dihydropyrimidin-2-ones have been synthesized and subjected to enantioselective deacetylation reactions mediated by different lipases in organic media. Novozyme 435 in tetrahydrofuran:diisopropyl ether was found to be the catalyst of choice for efficient enantioselective deacetylation of dihydropyrimidinones under study. Further, we discovered that lipase isolated from Pseudomonas aeruginosa can be used for selective acylation of secondary hydroxyl groups in nucleosides. This observation can be very useful for selective manipulation of different hydroxyl groups in nucleosides.
*Paper based on a presentation at the 24th International Symposium on the Chemistry of Natural Products and the 4th International Congress on Biodiversity, held jointly in Delhi, India, 26-31 January 2004. Other presentations are published in this issue, pp. 1-344.