Starting from 5-alkylidene or 5-benzylidenetetramic acid optically-active 4-amino-3-hydroxy-carboxylic acids are produced in the (rel-3R,4R) configuration, especially statine. The synthesis process includes the O-acylation of the tetramic acid to the corresponding 4-acyloxy-3-pyrrolin-2-one, a stereoselective hydrogenation to (rel-4R,5R)-4-acyloxy-5-alkyl or 5-benzylpyrrolidin-2-one and an enantioselective enzymatic hydrolysis of the (4R,5R)-enantiomer to the corresponding 4-hydroxypyrrolidin-2-one. The nonhydrolyzed enantiomer is separated and converted into the target compound with (3S,4S) configuration by hydrolytic cleavage of the lactam ring and the ester function and optionally introduction of an amino protective group. Analogously the (3R,4R)-enantiomer can be obtained from the 4-hydroxypyrrolidin-2-one from the enzymatic hydrolysis. The 4-amino-3-hydroxycarboxylic acids producible according to the invention are the structural elements of enzyme inhibitors.
从5-烷基亚
甲基或5-
苯甲基亚
甲基四元酸开始,通过合成过程制备出(rel-3R,4R)构型的光学活性4-
氨基-3-羟基-
羧酸,尤其是statine。合成过程包括将四元酸进行O-酰化,制备相应的4-酰
氧基-
3-吡咯烷酮,进行立体选择性
氢化制备出(rel-4R,5R)-4-酰
氧基-5-烷基或5-
苯甲基吡咯烷
酮,并进行对映选择性的酶催化
水解,制备相应的4-
羟基吡咯烷酮。未
水解的对映体被分离并通过内
酰胺环和
酯基的
水解以及可能的
氨基保护基的引入转化为具有(3S,4S)构型的目标化合物。类似地,(3R,4R)对映体可以从酶催化
水解得到的4-
羟基吡咯烷酮中获得。根据本发明可制备的4-
氨基-3-羟基
羧酸是酶
抑制剂的结构元素。