Question 1 On the next two pages are the MS, IR, 1H and 13C NMR, DEPT, COSY, and HETCOR spectra of an unknown compound. The molecular formula is C8H15BrO2. Please do the following: 1. Propose a structure for this compound. (10 points) 2. Assign the 1H NMR and 13C NMR spectra for your proposed structure. (15 points) Question 2 On the following four pages are the IR, 1H and 13C NMR, DEPT, COSY, HMBC and HMQC spectra of an unknown compound. The molecular formula is C11H20O3 (MW: 200). Please do the following: 1. Propose a structure for the compound. (10 points) 2. Assign the 1H NMR and 13C NMR spectra for your proposed structure. (15 points) Question 3 On the next several pages are the 1H, 13C, COSY, HMQC, HMBC and ROESY spectra of compound X. The structure of X is shown below. • Completely assign the chemical shifts on the 1H NMR and 13C NMR spectra of this compound using the numbering system shown below. (50 points)