Download CHEM 3311, Spring 2007 Exam 2: Organic Chemistry and more Exams Organic Chemistry in PDF only on Docsity! CHEM 3311-100 Spring 2007 Exam 2 Professor R. Hoenigman I pledge to uphold the CU Honor Code: Signature______________________________________________ Name (printed)____________________________________________________ Last four digits of your student ID number_______________________________ Recitation TA_____________________________________________________ Recitation number, day, and time______________________________________ You have 1 hour and 30 minutes to complete this exam. No model kits or calculators allowed. Periodic table and scratch paper are attached. DO NOT TURN THIS PAGE UNTIL INSTRUCTED TO DO SO. Recitation Sections: # Day Time TA SCORE: 121 Tuesday 8 am Kelly 131 Tuesday 1 pm Kelly Page 1 ________/10 Page 4_______/15 141 Wednesday 8 am Greg 151 Wednesday 12 pm Greg Page 2 ________/18 Page 5_______/10 153 Wednesday 12 pm Kelly 152 Wednesday 5 pm Kelly Page 3 ________/24 Page 6_______/23 171 Thursday 12 pm Greg TOTAL________/100 CHEM 3311, Spring 2007 Exam 2, page 1 of 6 1. (4 pts) Penicillin is one of the most widely prescribed drugs. Circle all of the terms below that describe one or more structural feature of penicillin G. Alcohol Aldehyde Alkene Amide Amine Aromatic ring Carboxylic acid Ester Ether Ketone Sulfide Thiol N S H N O O O HO penicillin G 2. (6 pts) Explain why 1-chloropentane (b.p. = 108 °C) has a lower boiling point than 1-iodopentane (b.p. = 157 °C). Please be specific in your answer. CHEM 3311, Spring 2007 Exam 2, page 4 of 6 6. (5 pts) Many organic chemists are involved in the synthesis of natural products (naturally occurring organic compounds). Akaloid (-)-205B (shown below) has been isolated from a frog found in Panama. One step (of many steps) in a recent synthesis of this natural product attempted to introduce the trans methyl substituents into the six-membered ring. N CH3 H H3C H H Alkaloid (-)-205B Partial Synthesis: O N CH3 H H2C H H O N CH3 H H3C H H O N CH3 H H3C H H + 80% 20% A. What kind of reaction is occurring? B. In the box above, propose reagents for this reaction. C. Why did this particular attempt fail? Why isn’t the major product of this reaction the desired compound with the trans methyl substituents? Hint: the starting material can also be drawn as: N CH3 H2C H 7. (10 pts) Fill in the organic product of the following reaction and, using arrows to show the flow of electrons, draw a mechanism to account for its formation. OH HI CHEM 3311, Spring 2007 Exam 2, page 5 of 6 8. (10 pts) Fill in the organic product of the following reaction and, using fishhook arrows to show the flow of electrons, draw a mechanism to account for its formation. Be sure to label any initiation, propagation, or termination steps. HBr HOOH CHEM 3311, Spring 2007 Exam 2, page 6 of 6 9. (23 pts) Propose an efficient synthesis for each of the following transformations. You may use any reagents you like. A. Br starting from 2-methylcyclohexanol B. cis-1,2-cyclopentanediol starting from cyclopentane C. O O + starting from 3,3-dimethyl-1-pentene
