摘要：

INTRODUCTIONSome time ago, a report has been published on acety- lation1 of pyrimidine nucleosides by the action of acetic anhydride in the presence of acetyl chloride; this reaction may be conducted in the solution of acetic acid as a suitable solvent of nucleosides. This so called "acid acety- lation" may also be performed on treatment with acetyl chloride alone. A simple work-up of the reaction mixture by evaporation and crystallisation of the residue makes the method particularly advantageous for the preparation of water-soluble acetyl derivatives. The method has been utilised in the preparation of acetylated ribo12, arabino2, and deoxy3-6 derivatives of pyrimidine nucleosides. Another

展开