(2R)-chlorobutane can undergo nucleophilic substitution with NaBr. This reaction can proceed through either an SN2- or an Syl-mechanism.

a) Draw the mechanism, including the stereochemistry, of this reaction, include
intermediate(s) if
present, when assuming the reaction proceeds through an SN2-mechanism.

b) Sketch the graphical course of this SN2-reaction with the change in energy as function of the
reaction coordinate.

c) Why would you prefer to avoid an SNl-mechanism when you aim to achieve an enantiomerically
pure product? Explain your answer using the intermediate of this mechanism.

d) Why would you prefer to avoid an Sn1-mechanism even in the case a racemic mixture would be
permitted?

Would appreciate if you could answer even if one question!