Problems and exercisesStrategies in asymmetric synthesis
Exercise 1
An asymmetric reduction gives a 92:8 mixture of the R and S alcohols. What is its enantiomeric excess? What energy difference between the two transition states is needed to obtain 98% ee at 25 °C and at −78 °C?
Exercise 2
In the kinetic resolution of racemic 1-phenylethanol with CAL-B and vinyl acetate, what is the maximum yield of each enantiomer? What happens to the ee of the remaining alcohol if the reaction is allowed to go beyond 50% conversion? How could all of the racemate be obtained as the R acetate?