(-)-Swainsonine is prepared by the steps of first reacting a compound having the formula: ##STR1## wherein each R.sub.2 is lower alkyl, with (4-carbalkoxybutyl) triphenylphosphonium bromide in a strong base to obtain an alcohol having the formula: ##STR2## wherein R.sub.2 is as defined above and R is C.sub.1 -C.sub.8 alkyl; the alcohol is then reacted with methanesulfonyl chloride or p-toluenesulfonyl chloride or benzenesulfonyl chloride in the presence of a tertiary amine to obtain the corresponding sulfonate. Heating the sulfonate with an azide in an organic solvent yields an imine having the formula: ##STR3## wherein R.sub.2 and R are ad defined above. Treating the imine with an inorganic base, in aqueous alcohol provides upon acidification, the corresponding acid. Heating the acid at reflux temperature in organic solvent, yields an enamide having the formula: ##STR4## wherein R.sub.2 is as defined above. Treating the enamide with diborane followed by reaction with hydrogen peroxide provides a protected swainsonine having the formula: ##STR5## which upon acid hydrolysis gives swainsonine.
(-)-Swainsonine的制备方法包括以下步骤:首先将具有以下
化学式的化合物:##STR1##其中每个R.sub.2是低级烷基,与(4-羧基丁基)
三苯基膦溴化物在强碱的作用下反应,得到具有以下
化学式的醇:##STR2##其中R.sub.2如上定义,R是C.sub.1-C.sub.8烷基;然后在三级胺的存在下,将该醇与甲
磺酰氯或
对甲苯磺酰氯或
苯磺酰氯反应,得到相应的
磺酸酯。在有机溶剂中将
磺酸酯与
叠氮化物加热反应得到具有以下
化学式的
亚胺:##STR3##其中R.sub.2和R如上定义。将
亚胺在
无机碱的存在下,在
水醇中进行处理,酸化后得到相应的酸。在有机溶剂中回流加热酸,得到具有以下
化学式的烯酰胺:##STR4##其中R.sub.2如上定义。将烯酰胺与二
硼烷反应,然后再与
过氧化氢反应,得到具有以下
化学式的保护型Swainsonine:##STR5##通过酸
水解,得到Swainsonine。