Name the type of reaction and outline the mechanism for the reaction of the alcohol (CH3)2CHOH with the acyl chloride CH3COCl. Explain which orbitals take part in the reaction.

Type of reaction: nucleophilic addition to carbonyl

Diagram should show nucleophilic attack of oxygen of alcohol on carbon of carbonyl in the acyl chloride. Lone pair clearly shown on the oxygen, full curly arrow drawn from said oxygen to carbon of carbonyl. Second full curly arrow drawn from middle of carbonyl bond to oxygen of carbonyl. Tetrahedral intermediate drawn with minus sign on carbonyl oxygenand positive sign on alcohol oxygen. Curly arrow comes down from minus sign into C-O bond, second curly arrow comes from middle of C-Cl bond onto the Cl. Third curly arrow drawn from middle of O-H bond on to the alcohol oxygen.

Orbital description involves oxygen lone pair as the HOMO and C-O pi* as the LUMO. Electronegativity difference in the carbonyl creates a dipole across the C-O bond and thus the negative lone pair attacks the slightly positive carbonyl carbon. Angle of approach allows for optimal orbital overlap, the orbitals overlap constructively (only very good candidates may have a grasp of orbital theory).