CHEM 2132L Quiz 1 10-21-97

  1. What was the purpose of the aqueous sodium bisulfite in the first part of the experiment where the bromine addition has been performed?

    2. To reduce the excess Br2
    Br2 2 Br-

  2. What was the purpose of refluxing diethylmaleate with zinc and ZnBr2?

    3. To check the stability of diethylmaleate under the reaction conditions.

  3. Describe each of the following reactions as stereoselective, stereospecific or neither.



  4. Draw the meso and d,l isomers of 2,3-butanediol and indicate which is which.

  5. Explain how you would differentiate between the following isomers:

    6. NMR or IR
    CH3 H’s are a singlet in this isomer     		NMR or IR
    in the ‘HNMR the vinylic H furthest downfield will be a doublet with     		NMR or IR
    in the ‘HNMR the vinylic H furthest downfield will be a double +
    with J » 10 Hz
    IR
    strong band»990 cm-1     		IR
    strong band »970 cm-1     		IR
    strong band »700 cm-1