頁籤選單縮合
題名 | A Concise Synthesis of the Antibiotic L-Azatyrosine= |
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作者 | 胡明寬; 汪政毅; Hu, Ming-kuan; Wang, Cheng-yi; |
期刊 | 中華藥學雜誌 |
出版日期 | 19981200 |
卷期 | 50:6 1998.12[民87.12] |
頁次 | 頁319-325 |
分類號 | 418.4 |
語文 | eng |
關鍵詞 | Antibiotic; L-azatyrosine; Enzymatic resolution; |
英文摘要 | A practical and economical synthesis of the naturally occurring antibiotic L-azatyrosine (1) in six steps with an overall yield of 10% is reported. The choice of commercially available 5-hydroxy-2-methylpyridine (3) as a starting material and a benzenesulfonyl group for hydroxyl protection (as 4) were critical to successful synthesis of the antibiotic. Enolate alkylation of diethyl 2-acetamido-malonate (6) with chemically stable 2-(bromomethyl)-5-benzenesulfonyloxy-pyridine (5) using potassium tert-butoxide as base efficiently produced the malonate adduct 7. Enzymatic resolution of the racemic N-acetyl azatyrosinate ethyl ester (8) was accomplished with α -chymotrypsin in aqueous DMF to afford separable N-acetyl-L-azatyrosine (9) and N-acetyl-D-azatyrsoinate ethyl ester (10). Hydrolysis of 9 in strong acid provided L-azatyrosine (1). |
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