Organic Chemistry CHE230-001 EXAM 3 Page 1 of 6 Cover Sheet! EXAM3 CHEM230-001 FALL 2002 PRINT your name legibly on the line below. _____________________________________________________Organic Chemistry CHE230-001 EXAM 3 Page 2 of 6 Name: ______________________ Student ID No:____________ First: You are allowed to have a writing utensil, a calculator and molecular model set at your seat. Please put away all other materials. Second: Place your student identification on your desk. A proctor will come around to check everyone’s ID. Is your name and number on your test? Third: Quickly read through the entire exam. Your goal, as always, is to score as many points as possible. Do not waste time on problems that you can’t do if there are easy questions to do first. Fourth: It is critically important that your answers be written in a clear, unambiguous manner. Answers in which your intentions are unclear will not receive credit. SHOW YOUR WORK! Fifth: READ THE INSTRUCTIONS FOR EACH PROBLEM. answer each question Problem Number Points possible Score 1. 50 _____ 2. 10 _____ 3. 20 _____ 4. 10 _____ 5. 10 _____ 6. 10 (bonus) ______ Total 100 _____Organic Chemistry CHE230-001 EXAM 3 Page 3 of 6 1. (50 pts) Draw the most likely product(s) to the right of the reactions and label them clearly A-J. Hints: A-B, and E-J have stereochemical issues; in some cases you have to evaluate which is the least hindered side of the molecules, in other cases cis versus trans etc. Pay attention to regiochemistry—most stable carbocation. E and F are rearranged addition products. The bonds that interact best with the carbocation are the ones most likely to shift to the most stable carbocation. H is a racemic mixture of enantiomers, draw one enantiomer. H2Pd/C/CaO3/PbLindlar catalystANa / NH3B1) BH3 / ether2) H2O2 / NaOH / H2OCH3O / H2ODH3O / H2OE + Fdiastereomers1) OsO4, iPrOH2) NaOH, H2OG1) BH3 / ether2) H2O2, NaOH, H2OH1) Cl2, H2O2) NaOH, H2OIJOrganic Chemistry CHE230-001 EXAM 3 Page 4 of 6 2. (10 pts) Draw the starting material 2A. 2A has only 3 signals in its 13C NMR spectrum. OOHOHO1) O3, CH2Cl22) H2O2, H2O2A 3. (20 pts) Answer the following question in reference to the reaction energy diagrams below. The labeled points on the reaction energy diagrams are either energies or chemical species, depending on the sentence. 3a. ______ might be a catalytic intermediate or even a carbocation. 3b. ___________ This difference in energy might determine the rate of an SN2 reaction. 3c. ___________This difference in energy might determine the ratio of product to starting material of an E1 reaction. 3c. The Hammond postulate states that D is most similar in structure to _______. EnergyReaction CoordinateABCDEFGHOrganic Chemistry CHE230-001 EXAM 3 Page 5 of 6 4. (10 pts) Rank the following carbocations by stability from 1-5. Use 1 as the most stable! Pick the most stable 4 pts. Pick the least stable 4 pts. OHHH2CHHHHHOHH3CHHHHHHOHH3CHHHHHHHOHHH3CHHHHHHHHH 5. (10 pts) In general additions reactions of double and triple bonds are (exothermic or endothermic)_______________________________ because _________________ ___________________________________________________________________ ____________________________________________________________________ ____________________________________________________________________ 6. (10 pts. bonus) Starting from molecules possessing five carbon atoms or less, draw the chemical equations needed to show how you would synthesize 6A. Remember that the conjugated bases of terminal alkynes can be used as nucleophiles in substitution reactions.
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