1. The overall $\Delta_rG^\circ$ values for formation of compounds I and II from but-3-en-2-one + HCN at 20 °C are, respectively, -30 kJ mol⁻¹ and -50 kJ mol⁻¹ (Note: These $\Delta_rG^\circ$ values have not been measured; they are included here just for the purposes of this question). If the reaction is conducted at 0 °C, the product isolated is I.
I
CN
OH
Intermediate
A
+
Intermediate
B
NC
HCN
II
Reactants
Draw curly arrow mechanisms for each of the possible reactions (formation of I and II).
Determine which reaction is more thermodynamically favoured, and explain why it is thermodynamically favoured.
Determine which reaction gives the kinetic product, and explain why the reaction pathway in question is kinetically favoured.
Draw a fully labelled Gibbs energy profile diagram for these reactions, showing the relative Gibbs energies of all species in the reaction.
How can one favour the formation of II?
