d-Ribono-1,4-lactone was treated with ethylamine in DMF to afford N-ethyl-d-ribonamide 9a in quantitative yield. Bromination of amide 9a by the system SOBr2 in DMF or PPh3/CBr4 in pyridine led, after acetylation, to epoxide 7. However, treatment of amide 9a with acetyl bromide in dioxane followed by acetylation gave 2,3,4-tri-O-acetyl-5-bromo-5-deoxyl-N-ethyl-d-ribonamide 10a. Methanolysis of 10a, with
d -Ribono -1,4-内酯与
乙胺的
DMF溶液处理,得到Ñ乙基d -ribonamide 9A,定量收率。乙酰化后,
DMF中的SOBr 2或
吡啶中的PPh 3 / CBr 4导致酰胺9a
溴化,生成
环氧化物7。然而,治疗酰胺9A与在
二恶烷乙酰溴,然后乙酰化,得到2,3,4-三ø -乙酰基-5-
溴-5- deoxyl -N -乙基- d -ribonamide 10A。用
甲醇钠将10a
甲醇分解,得到N乙基d -ribonolactam 11A在51%的总产率。使用这种方法,Ñ丁基,Ñ -己基,Ñ
十二烷基,和Ñ苄基d -ribonolactams 11B - ë是在良好的产率(48-53%)获得。