ansa-Metallocene derivatives - XII. Diastereomeric derivatisation and enantiomer separation of ethylenebis(tetrahydronindenyl)-titanium and -zirconium dichlorides - Schafer, A.; Karl, E.; Zsolnai, L.; Huttner, G.; Brintzinger, H.-H. (Elsevier)
Derivatisation of racemic ethylene-bridged bis(4,5,6,7tetrahydro-1-indenyl)-titanium and -zirconium dichlorides with O-acetyl-r-mandelic acid affords diastereomers which can be separately crystallised. Crystal and molecular structures of these diastereomers reveal different chelate ring conformations in the crystalline state. The separated diastereomers have been converted, via their dimethyl derivatives, into the corresponding titanocene and zirconocene dichloride enantiomers, the optical purity of these enantiomers has been demonstrated by their reconversion into the acetyl-r-mandelate derivatives.
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