given the reaction: Reaction of Dimedone andBenzaldehyde (2 Part)

overview Part 1:

Using a Pasteur pipet, add 0.2 g ofbenzaldehyde to 50 mL Erlenmeyer flask. 2. Add 8mL of 1:1 ethanol/water and swirl the flask to mix thecontent. 3. Add 0.6 g of dimedone and 3drops of piperidine, and 2-3 boiling chips 4. Boil gentlyfor 5 min on a hot plate 6. at the end of 5 minutes let the mixturecool, followed by cooling in an ice bath to completecrystallization5. Collect crystals by vacuum filtration, washingwith several 10 mL portions of ice cold 1:1 ethanol: water, Gentlybreak the crystals with a spatula and let them sit on the vacuumfor 30 min to dry.

overview Part 2:

Next if 250mg of product (from above) and 10 ml of absoulteenthanol were put into an erenmeyer flask, heated. Then 2.5ml ofwater and 6 drops of 6M HCL were added. The mixture was left to tocontinue  boiling. the flask was removed fro heat andwater was added dropwise until the mixture becomes cloudy. Theproduct is collected.

Questions:

1. why is it possible for dimedone to have two tauromers?

2. what spectroscopy methods can you use to prove the formationof tautomers?

3. why do you use piperdine during the first step of thisreaction? could you use inorganic base instead?

4. what are the differences in IR between benzaldehyde and theproduct from part 2(3,3,6,6-tetramethyl-9-phenyl-3,4,5,6,7,9-hexahydro-1h-xanthene-1,8(2h)-dione)