1. Nitroethane [CH3CH2NO2, pKa=8.6] is a much stronger acid than ethane [CH3CH3, pKa > 60]. Explain

2. Write a complete stepwise mechanism for the reaction of cyclopentanone with bromine in acetic acid to give 2-bromocyclopentanone. Show all intermediate structures and all electron flow with arrows.

3. In the alkylation of cyclohexanone, better yields are obtained by first reacting cyclohexanone with an equivalent of lithium diisopropylamide in THF and then adding the alkyl halide, rather than mixing cyclohexanone, akyl halide, and a catalytic amount of sodium ethoxide in ethanol. Explain this observation by pointing out what the problems with the second reaction conditions might be and how the first set of reaction conditions help alleviate the problems.

4. Ethyl acetate can be prepared from ethanol as the only organic starting materal. Show all reagents and structures for all intermediates in this preparation.

5. Consider the compound 2-methyl-2-carboethoxycyclopentanone (structures wasn't provided)

Formulate a synthesis of 2-methyl-2-carboethoxycyclopentanone starting with acyclic precursors using a Dieckmann cyclization as a key carbon-carbon bond forming step. Show all reagents and all intermeidate structures.

6. Oxaloacetic acid is an important inetermediate in the biosynthesis of citric acid. Synthesize oxaloacetic acid using a mixed Claisen condensation as a key carbon-carbon bond forming reaction.