Pinane absolute

The bidentate phenanthroline derivative L9b (Fig. 5) having a pinane skeleton was found to give a good to excellent % ee 75.6% for acetophenone, better than the phenathroHne-oxazoHne L9a as a tridentate Hgand [28]. The tetraden-tate bis(oxazolinyl)-bipyridine Bipymox (LIO) exhibited 90% ee in its RhClj complex [29]. The absolute configuration, S, of the product alcohols was obtained in the same way as in the case of Pybox L8. 

The problem was expected to be solved by chemical degradation to authentic cis-pinane, the levorotatory enantiomer of which has the absolute configuration (1S,2R,5S). Provided that the degradation exactly yields this enantiomer, as identified by value and sign of its specific rotation, then the asymmetric carbon centers of the sesquiterpenes 1 and 4 certainly possess the absolute configurations (15,55). 

In complexation gas chromatography, semipreparative separations of spiroketals (among them pheromones) have been reported. The preparative invertomer separation of l-chloro-2,2-dimethylaziri-dine permitted the determination of chiroptical data, absolute configuration and inversion barrier. Very large separation factors a were observed for saturated hydrocarbons (cis- and tra s-pinane, camphene) on a mixture of a-cyclodextrin in form-amide impreg/nated on celite. The preparative enantiomer separation of a-ionone on (18) and of all-trans-perhydrotriphenylene on (25) has been described. The large separation factors observed for the inhalational anesthetics enflurane, isoflurane, and desflurane on (18) allowed their enantiomer separation for subsequent biomedical trials and acquisition of chiroptical data. The continuous preparative enantiomer separation of enflurane and... 

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