作者:Sergei?I. Kozhushkov、Dmitrii?S. Yufit、Armin de?Meijere
DOI:10.1002/adsc.200404296
日期:2005.2
treatment with aqueous 6 N HCl and then ammonia solutions. The same transformations of (1R,2R)-9 [prepared by deracemization of rac-9 with (−)-dibenzoyl-L-tartaric acid (DBT)] proceeded without loss of the optical activity. Deracemization of rac-1 applying (+)-(S)-L-mandelic acid (MA) furnished (1R,2R)-1 and (1S,2S)-1 in 34 and 17% yield, respectively, with e.e. ≥ 98 and 97.6%, respectively. Procedures
外消旋的反式-1-氨基-6-硝基茚满-2-醇(rac - 1)是由廉价的茚(7)分五步制备的,总收率为96%。关键步骤是将已知的反式-1-氨基茚满-2-醇(rac - 9)直接硝化,得到硫酸单-(rac-反式-1-氨基-6-硝基茚满-2-基)酯(rac - 10),定量收率。通过先后用6 N HCl水溶液和氨溶液处理将后者定量转化为rac - 1。(1 R,2 R)-9的相同变换[通过用(-)-二苯甲酰基-L-酒石酸(DBT)对rac - 9进行消旋处理制备],而没有损失光学活性。应用(+)-(S)-L-扁桃酸(MA)对rac - 1进行脱硫处理,分别获得(1 R,2 R)-1和(1 S,2 S)-1的产率为34%和17%,与EE ≥98和97.6%之间。还描述了手性助剂DBT和MA的回收程序。通过X射线晶体结构分析确认了关键中间体的结构。