Enantioselektivni reakce.

As a part of research programme aimed at enantioselective reductions of prochiral carbonyl group simple and very efficient resolution method of both enantiomers of 2,2-dihydroxy-1,1- binaphtalene-3-carboxylic acid was developed. This synthon has great possibilities for next conversions to the other chiral compounds. In our case, on the basis of reactions known for racemic mixtures, a method for preparation of 1,1-binaphtalene-2,2- diols substituted at position 3- with oligoethylenglycolic chains of different lengths was developed. Reaction conditions for racemic mixtures of compounds of this type are not applicable for the pure enantiomers, because racemization occurs. Therefore selected reagents and reaction conditions had to be adapted that way to prevent the racemization. Prepared compounds were used as chiral modifies of lithium aluminium hydride used for reduction of prochiral carbonyl groups. Reduction with this chiral reagent did not lead to better or at least comparable results as in case of other known reagents. We observed some enantioselectivity of reduction with our reagent even when temperature was enhanced, but reached e.e. was only about 40%. Prepared compounds are therefore the most useful in the field of analytical chemistry, for instance for enantioselective complexation of amino acids derivatives or for preparation of chiral stationary phase for HPLC columns.Available from STL, Prague, CZ / NTK - National Technical LibrarySIGLECZCzech Republi