脂肪二醇对映体的气相色谱直接分离

Direct Separation of Enantiomers of Aliphetic Diols by Gas Chromatography

Some enantiomers of aliphatie vicinal diols,which are important as starting com- pounds for the synthesis of natural products,can be well separated by GC on a Chirasil -Val column without derivatization,if the column is efficiently deactivated.The resolution is nearly to baseline and without obvious tailing.It is noted that the resolution of enan- tiomers of diols after proper derivatization on either metal complexes or diamide phases, such as Chirasil-Val,has been described,but these methods have certain disadvantages,e. g.time consumption,side reactions and raeemization,as compared to the more convenient direct resolution.The results are compared to the cyclic carbonates,prepared by reaction of the diols with phosgene.No advantage in retention time and resolution factor on Chirasil- Val has been observed for such derivatlves.The Kovats index and the temperature coefficent for both diols and their derivatives have been calculated.Differences in the index-temper- ature relation between the two classes of compounds are demonstrated.Thermodynamic n- alysis has done also for these compounds and the peak reversal for some enantiomer pairs is predicted.The direct resolution is particularly useful for the determination of the enatio- merle purity,thus allowing also the precise measurement of the degree of racemization occuring in any derivatization method used.