【摘要】 应用 N-羧酰咪唑在合适的条件下可按制备性规模进行选择性地酰化核糖核苷酸和核糖核苷,得率为50—80%.对反应机制作了初步探讨.更多还原

【Abstract】 Selective acylation of ribonucleotides and ribonucleosides can be achieved by usingN-acylimidazole on a preparative scale with good yields(50—80%).For uridine-3′-phosphate(U_p):in the presence of MDCAI,the 2′-O-acyl-derivative was the mainproduct,while in the presence of an excess of TEAH,the 5′-O-acyl-derivative wasthe main product.For ribonucleosides(U_R or A_R or ψ_R):in the presence of MDCAI,theacylation took place preferably on 2′-OH or 3′-OH of ribonucleoside and only 3′-O-acyl-derivatives can be isolated by crystalization;in the presence of an excess of TEAH′5′-O-acyl-derivative was obtained as the main product.Arabonuleoside anddeoxyribonucleoside were only slowly acylated to form 5′-O-acyl-derivatives as themain products by acylimidazole in the presence of MDCAI.Possible mechanisms ofacylation were discussed.更多还原