Question

5) A substrate controled reaction is one which can furnish a product with high enantiomeric purity in which the stereochemistry of the starting material helps to control for the stereochemistry of the product. Below is an example of a substrate controlled reaction using chelation controlled addition of m-CPBA to the cycloalkene. Notice that only the top face as drawn obtains the oxygen of the epoxide as a result of hydrogen bonding of the chiral alcohol to the m-CPBA reagent. OH OH OH Ar H--O Ph Ph Ph Ph a) Indicate which product should be the major isomer and which one should be the minor isomer B) If hydrogen bonding were disrupted by using an additive, how might this effect the enantioselectivity for this reaction?

Answer 1