A new class of axially-chiral o,o′-bridged biphenyls containing etheroxime chains was obtained in good yields by the macrocyclisation reaction of o,o′-diformylbiphenyl dioxime with several ditosylated or dibrominated reagents. In all cases the enantiomers of the compounds were separated by HPLC using a chiral column (Chiralpack IC) and the stability of the enantiomers (barriers of racemisation) was investigated employing chiral HPLC or chiral Dynamic HPLC techniques. A slight influence on the barrier to rotation was noticed when the enantiomerisation was performed in the presence of suitable alkali cations.

中文翻译：

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“Geländer”大环化合物：合成，手性和外消旋化障碍

一类新的轴向手性的Ö，ö “被以良好的收率由的大环化反应得到的含-bridged链etheroxime联苯-O，O '-diformylbiphenyl二肟与几个ditosylated或二溴化试剂。在所有情况下，使用手性柱（Chiralpack IC）通过HPLC分离化合物的对映异构体，并使用手性HPLC或手性动态HPLC技术研究对映体的稳定性（外消旋的障碍）。当在合适的碱金属阳离子存在下进行对映异构时，发现对旋转壁的影响很小。