31 Solved Problems on Organic Chemistry II - Exam 1 | CH 310N, Exams of Organic Chemistry

Download 31 Solved Problems on Organic Chemistry II - Exam 1 | CH 310N and more Exams Organic Chemistry in PDF only on Docsity! LAST NAME: FIRST NAME: UTEID: Instructions This exam will be closed book. No notes, books, calculators, or molecular models will be allowed. The exam will be comprised of two distinct parts: Part I will consist of a series of multiple choice questions. Your answers to these questions must be submitted on a Scantron “bubble” sheet. The answer sheet will be provided for you, but you will need your own #2 pencil(s). Only answers marked on the bubble sheet will be graded. Answers to Part I questions marked on the exam itself cannot not be graded. No re-grades will be possible on Part I of the exam. Part II consists of questions for which you will need to write out your answers, using structures and/or words. This part of the exam will be hand-graded. Answers for the Part II questions that are written in pencil will not be eligible for re-grades. Answers written in pencil with ink overlay will not be eligible for re-grades. If you use a pen to answer the Part II questions, only blue or black ink is acceptable. Answers written in red ink cannot be graded. 1. You must have your valid UT ID card (or other government-issued ID) with you. You will need to show it to the proctors when you turn in your exam. 2. Chapter 4 of the University’s “General Information” catalog outlines this university’s policies regarding exams, as well as other quizzes administered during the semester. Specifically, students are expected to remain in the exam room until a test is completed. These policies will be strictly enforced, with no exceptions. You may not leave the room for any reason until you are ready to turn in your exam. If you wish to leave the room, you will need to turn in your exam to the proctors, and you will not be allowed to return. Please, plan accordingly by using the rest room before the exam starts. CH 310 N Exam I Question Value Score 1 15 2 16 3 12 4 15 5 8 6 9 Section II 75 Section I 75 Raw Total 150 Grade UTID: ________________________ September 2011 1 CH310N-Exam I Objective Test Section Identify the choice that best completes the statement or answers the question. There is only one correct answer; please carefully bubble your choice on the scantron sheet. (3pts. ea; 75 pts this section) 1. Which feature in the 1H NMR spectrum provides information about the number of types of different protons in a compound? a. number of signals b. chemical shift c. integral d. splitting 2. Which combination(s) of alkyl bromide and carbonyl compound can be used to prepare the following product by addition of the Grignard reagent derived from the alkyl bromide to the carbonyl compound? a. only 1 b. only 3 c. only 1 and 3 d. only 2 and 4 3. What is the major organic product obtained from the following reaction? a. 1 b. 2 c. 3 d. 4 4 10. What is the major organic product obtained from the following sequence of reactions? a. 1 b. 2 c. 3 d. 4 11. What is the major organic product obtained from the following sequence of reactions? a. 3-methyl-2-butanol b. 3-methyl-2-butene c. 3-methyl-1-butanol d. 2-methylbutane 12. What is the major organic product obtained from the following reaction? a. 1 b. 2 c. 3 d. 4 5 13. Which feature in the 1H NMR spectrum provides information about the electronic environment of the protons in a compound? a. splitting b. chemical shift c. integral d. number of signals 14. What is the major organic product obtained from the following reaction? a. 1-butene b. 2-methyl-1-propanol c. 2-methylpropene d. 2-butene 15. What is the relationship between the following two structures? a. resonance structures b. tautomers c. stereoisomers d. constitutional isomers, but not tautomers 16. What is the major organic product obtained from the following reaction? a. 1 b. 2 c. 3 d. 4 6 17. Which of the following is the best choice of solvent for the formation of phenyllithium by the reaction of bromobenzene with lithium? a. ethanol b. water c. tetrahydrofuran d. acetic acid 18. Which of the protons in the following molecule appear furthest downfield in the 1H NMR spectrum? a. i b. ii c. iii d. iv 19. What is the major organic product obtained from the following reaction? a. 3-phenylbutanone b. 3-phenyl-2-butanol c. propiophenone, PhCOCH2CH3 d. 2-phenyl-2-butanol 20. Which feature in the 1H NMR spectrum provides information about the number of neighboring protons of each proton in the compound? a. chemical shift b. number of signals c. integral d. multiplicity 21. Which of the protons in the following molecule appear furthest downfield in the 1H NMR spectrum? a. i b. ii c. iii d. iv CH 310 N EXAM #1 UTEID 8 KEY PART 2: Free Style Answer Format (75 pts in this section) 1) Reactions: Provide the reagents for the following reactions. Number the steps, if more than one is required. (3 pts per box) MgBr 1) 2) H3O+ 1) 2) H3O+ 1) 2) H3O+ 1) 2) H3O+ 1) 2) H3O+ H3C H O OH H OH CH3 OH CH2CH3 H3C CH2CH3 O H H O O OH CH3 O CH3 OH CH3 (racemic) (racemic) (racemic) CH 310 N EXAM #1 UTEID 9 KEY 2) Mechanism: Provide a mechanism for the following transformation. Show all important flows of electrons, charges and intermediates. Where indicated, (in the structure-n-a- box)- draw the intermediates. (16 pts) CH 310 N EXAM #1 UTEID 10 KEY 3) Texas two-step: Provide both the reagents (in square boxes) and the product (rounded box) for these synthesis. (Note, that a second reagent may be required in the square boxes. For example, the acid step of a Grignard addition.) (12 pts): 4) Multi-step synthesis: Provide the reagents for the following conversions. (15 pts) H2CrO4 CH3Ph Br2 heat or h CH2Br 1) Mg 2) CH3CHO 3) H3O+ C H2 CH3 OH Ph C H2 CH3 O Ph C H2 CH3 N Ph CH3 C H2 CH3 HN Ph CH3 H2; Ni or NaBH3CN CH3NH2