The preparation of compound 5 can be achieved using the synthetic route shown in Scheme.
a. Use correlation tables to predict an approximate value for the peaks you would expect to see in the 13C NMR spectrum of compound 3. For each signal predict how it would appear in DEPT-135, DEPT-90 and DEPT-45 (that is positive signal, negative signal or absent).
b. What type of compound is 2? Suggest appropriate reagents and reaction conditions which could be used to transform compound 1 into compound 2. Show the mechanism of the reaction using curly arrows.
c. Suggest a structure for compound 4 based on the reagents and starting materials shown for this step and the reagents and products for the following step. In what wavenumber range of the infrared spectrum would you expect to find a carbonyl stretch for 4.
d. Suggest one 13C NMR method (either broadband decoupled or DEPT) and one other spectroscopic method which could be used to identify compound 5 and for each describe what you would expect to see in the spectrum.
e. How would you determine if the final product were pure?