chem236-2009fa-hex4-key - Fall 2009 Chemistry 236 Hour Exam...

Info icon This preview shows pages 1–4. Sign up to view the full content.

View Full Document Right Arrow Icon
Chemistry 236 Hour Exam 4 Fall 2009 Last Name _______________________________ First Name _______________________________ 1. _______ 20 pts 2. _______ 12 pts 3. _______ 36 pts 4. _______ 10 pts 5. _______ 10 pts Total: __________ 100 pts 6. _______ 15 pts KEY ANSWER 20 12 36 10 10 15 103
Image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
1. A compound whose 1 H NMR spectrum is shown below has the molecular formula C 5 H 10 O 2 a. (5 points) Calculate the degrees of unsaturation - show your work. b. (5 points) Given the NMR above, the degrees of unsaturation that you calculated, and that the 13 C NMR shows peaks at δ 146.1, 110.8, 71.1, and 29.4 ppm, propose a structure. degrees of unsaturation = 2 x 5 - 10 + 2 2 = 1 1 degree of unsat means C=O or C=C or ring. C13 does not indicate carbonyl but does show alkene. Only four peaks means two carbons are probably magnetically equivalent, which is consistent with 1 H NMR. Looks like three alkene protons in NMR spectrum and broad peak at 3.6 ppm could be -OH. Really only one structure fits this: OH
Image of page 2
3 c. (10 points) For the three resonances between δ 5-6 ppm, show tree diagrams that explain the splitting patterns. Label protons on your structure, the NMR spectrum and the coupling constants on your tree diagrams (e.g., H
Image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Image of page 4
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern