A single enantiomer of N-benzyl-α-phenylethylamine is used as a resolving agent for racemic 1-alkoxycarbonyl-2-hydroxymethylcyclopropane-1-carboxylic acid. The latter may be produced by adding an equivalent amount of an alkali to 3-oxa-2-oxobicyclo[3.1.0]cyclopropane-1-carboxylic acid ester in solution. Reaction of the amine and carboxylic acid takes place in a selected solvent, and the resulting diastereomer salt which crystallises but may be filtered off. This may be subsequently decomposed with an alkali, and the resolution agent extracted into an organic solvent and then recovered. Thereafter, the aqueous phase is adjusted to an acid pH, to recover 3-oxa-2-oxobicyclo[3.1.0]hexane-1-carboxylic acid ester at a high optical purity, through solvent extraction.
N-苄基-
α-苯乙胺的单一对映体可用作外消旋 1-烷氧羰基-2-
羟甲基环丙烷-1-
羧酸的溶解剂。后者可通过向溶液中的 3-氧杂-2-氧代双环[3.1.0]
环丙烷-1-
羧酸酯中加入等量的碱来制得。胺和
羧酸在选定的溶剂中发生反应,生成非对映异构盐,这种盐会结晶,但可以过滤掉。随后可以用碱进行分解,并将分解剂萃取到有机溶剂中,然后进行回收。然后,将
水相调节至酸性 pH 值,通过溶剂萃取回收高光学纯度的 3-oxa-2-oxobicyclo[3.1.0]hexane-1-carboxylic acid ester。