Chem2O6 - 1997/98

1. Predict the principal products of the following reactions, showing stereochemistry where appropriate.

2. Predict the principal products of reaction of 1-methyl-2-(phenylethynyl)cyclohexene (A) with the following reagents, showing stereochemistry where appropriate:

(a) H₂ / Pd

(b) H₂ / Pd / CaCO₃ / quinoline

(c) Li / NH₃(liq)

3. Using a crude graph, draw simple line sketches of the ¹H nmr spectra expected for all the isomeric ethers of constitutional formula C₄H₁₀O. Expected chemical shifts should be accurate to within 0.5 ppm, and within each spectrum, the relative heights of the lines are to be proportional to the number of protons responsible for each of the predicted absorptions.  Do not skew multiplets. The predicted spectrum of ethanol is shown below as an example of what is expected.

4. The infrared and ¹H nmr spectra of a compound with molecular formula C₆H₁₁O₂Cl are shown below. Deduce the structure of the compound from these data.

5. The infrared and ¹H nmr spectra of a compound with molecular formula C₄H₇O₂Cl are shown below. Note that the multiplet at d~2 ppm in the nmr spectrum is a pentet. Deduce the structure of the compound from these data.

6. The following incomplete reaction sequences give only a starting material and a product that can be prepared from it by a multistep reaction sequence. Show the reagents that would that would be necessary to carry out each transformation, and any major products that would be formed in the intermediate stages.

Make sure that your answers are STAPLED TOGETHER and labelled with:

Assignments are due at 5pm on Friday, January 9 (in your Tutorial Leader's DropBox in ABB). Late assignments will receive a grade of ZERO, unless a medical slip is filed with the Dean's Office.

07dec97; wjl