1. The structure below is for the ester methyl isobutanoate (old name methyl isobutyrate) or even methyl - (2 methyl)propanoate. CHC -0CH3 | CHE Sketch 1. A proton NMR for this compound that shows coupling and reasonable chemical shifts. (4 marks) 2. An IR that shows at least 3 absorbances that would be seen for this molecule. (3 marks) 3. A mass spectrum that shows the molecular ion (M+) and the two peaks that would form from the most likely fragmentation