(1S,2S,5R,6S)-2-Aminobicyclo[3.1.0]hexane-2,6-dicarboxylic acid (LY354740) was synthesised enantiospecifically from a sugar derived enantiomerically pure cyclopentenone. The α-amino acid stereogenic centre was formed by reacting the ketone with chloroform anion and then the alcohol so formed was reacted with sodium azide/DBU in methanol to give an azido ester. Critically, this modified Corey-Link reaction gives the opposite stereochemical outcome to the traditional Bucherer-Bergs and Strecker reactions. The azide was reduced and acylated, the 1,2 diol deoxygenated and the protecting groups removed to give LY354740 with an e.e.>98%.

中文翻译：

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通过修饰的Corey-Link反应对映体合成（1S，2S，5R，6S）-2-氨基双环[3.1.0]己烷-2,6-二羧酸

（1S，2S，5R，6S）-2-氨基双环[3.1.0]己烷-2，6-二羧酸（LY354740）是由糖衍生的对映体纯的环戊烯酮对映体特异性合成的。通过使酮与氯仿阴离子反应形成α-氨基酸立体异构中心，然后使如此形成的醇与叠氮化钠/ DBU在甲醇中反应，得到叠氮酯。至关重要的是，这种改良的Corey-Link反应为传统的Bucherer-Bergs和Strecker反应提供了相反的立体化学结果。将叠氮化物还原并酰化，将1,2二醇脱氧并除去保护基，得到ee＞ 98％的LY354740。