The objective of this work was to develop a precise and accurate method to determine enantiomeric excess
This finding is consistent with those of our own scientists who have also detected significant reductions in product yields and enantiomeric excess
resulting from the trace moisture contamination of DPC.
This produces a chiral propanoic acid derivative with an enantiomeric excess of either the R or S enantiomer.
From this, the enantiomeric excess can be determined.
In our investigations, we have employed parallel reaction techniques to determine the influence of various parameters (temperature, concentration of substrate, additive and catalyst) on product yield and enantiomeric excess for the catalytic and stoichiometric epoxidation of cis-[beta]-methylstyrene.
The results of the reduction reactions indicated that as the number of stereogenic centers increased at the linking point on the polymer, the % enantiomeric excess of the alcohols produced during the reaction also increased from 13 % enantiomeric excess to 54 % enantiomeric excess.
The % enantiomeric excess was determined by comparing the areas of the R and S isomers relative to the area of a hydrocarbon reference.
However, the degree of chiral induction was rather low at 13 % enantiomeric excess.
The degree of chiral induction increased to 54 % enantiomeric excess.
While the native enzyme gives a two percent enantiomeric excess
in favour of the (S)-isomer, one of their mutated enzymes provided a 93 percent enantiomeric excess
in favour of the same enantiomer.
5 h with moderate enantiomeric excess
(ee 37%, kinetic resolution of the initial racemic compound occurred).
2] Amount of Enantiomeric excess
Entry catalyst Yield, % ee ** 1 5 mol% 5 26% 2 5 mol% 43 Rac + regio-isomers 3 1.