Question

1. A portion of NMR spectrum of 4-tert-butylcyclohexanol is shown below, along with a peak list of chemical shifts, multiplicities, and numbers of protons (from integration). Note: the alcohol O-H proton is NOT observed in this NMR spectrum.

a) The spectrum is consistent with a single isomer of 4-tert-butylcyclohexanol. Which one is it, cis or trans?

This spectrum is consistent with one isomer, the cis-4-butylcyclohexanol isomer.

a. Copy into your lab report the picture shown below the spectrum. Circle the structure of the correct isomer identified in (a).

http://www.chemicalbook.com/SpectrumEN_937-05-3_1HNMR.htm  image is located on this url it wouldnt let me paste. Same image used for part b,

b. Within the circled structure, circle the most important proton or protons that informed your answer to part (a).

c. What peak or peaks in the spectrum peak list correspond to the circled proton or protons in part (c)?

e) In this molecule, what conformational relationship between two coupled protons determines their coupling constant to each other (J values)?

f) For the selected peak(s) in (d), explain the multiplicity. Be as specific as possible by referring to the labeled protons in your circled structure and highlighting relevant coupling constants.

1H NMR spectrum peak list, ppm (multiplicity, number of protons)

4.03 (pentet, 1 H)

1.84 (multiplet, 2 H)

1.69 (singlet, 1 H)

1.54 (multiplet, 2 H)

1.45 (multiplet, 2 H)

1.37 (multiplet, 2 H)

0.99 (multiplet, 1 H)

0.86 (singlet, 9H)

Answer 1