In addition to predicting the enantiomers of the products from the reduction reactions, students were also expected to calculate the enantiomeric excess for their products. Students achieved enantiomeric excess for the CBS-catalyzed reactions in the range of 70-99.9%. The variations in yields and enantiomeric excess by the various groups led to meaningful discussions about how minor changes in reaction conditions like ice bath temperatures above 6 ˚C, speed of addition of the acetophenone solution or concentration of acetophenone solution added to the reaction mixture could lead to variations in the ee. Ultimately the ideal reaction condition depends on the reaction mechanism and transition states (thermodynamic/kinetic factors in the reaction) which is a perfect illustration of the need to understand reaction mechanisms. All student groups got products for analysis from their CBS reductions.