Exam 2 Questions - Organic Chemistry 1, Spring 2006 | CHEM 3311, Exams of Organic Chemistry

Download Exam 2 Questions - Organic Chemistry 1, Spring 2006 | CHEM 3311 and more Exams Organic Chemistry in PDF only on Docsity! CHEM 3311 Spring 2006 Exam 2 March 16, 2006 Professor Rebecca 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 15 minutes to complete this exam. No model kits or calculators allowed; periodic table and scratch paper are attached. DO NOT TURN PAGE UNTIL INSTRUCTED TO DO SO. Put your name on ALL pages of the exam Recitation Sections: Number Day Time TA 121 Tuesday 8 am Andrew 131 Tuesday 1 pm Heather 141 Wednesday 8 am Chris 151 Wednesday 12 pm Andrew 153 Wednesday 12 pm Nicole 152 Wednesday 5 pm Chris 171 Thursday 12 pm Heather Score: Page 1 ___________/15 Page 2 ___________/20 Page 3 ___________/21 Page 4 ___________/8 Page 5 ___________/24 Page 6 ___________/12 Total ______________/100 Average Score = 55 High Score = 98 Low Score = 7 Name: _________________________________ 1 1. (3 pts) Give the molecular formula for three stable inorganic radicals. (1 point each) O2 NO NO2 2. (12 pts) You have available 2,2-dimethylcyclopentanol (A) and 2-bromo-1,1- dimethylcyclopentane (B) and wish to prepare 3,3-dimethylcyclopentene (C). Which would you choose as the more suitable reactant, A or B, and with what would you treat it? Give an explanation for your choice. OH Br A B C Book Problem 5.43 (2 points for choosing correct reagent, 4 points for giving an example of a strong base, 6 points for the explanation) B is the more suitable reactant because it can undergo an E2 reaction with a strong base (such as CH3O -) to give only compound C. Compound A will undergo an E1 reaction, and since the cation intermediate will rearrange, compound C will be a minor product. Name: _________________________________ 4 6. (8 pts) Circle the relationship between the following pairs of compounds. (2 points each) A. Book Problem 7.33e CH2OH CH2OH OHH CH2OH CH2OH HHO Identical constitutional isomers enantiomers diastereomers B. Book Problem 7.33j HO CH2OH CH2OH HO Identical constitutional isomers enantiomers diastereomers C. CH3 Cl H H CH3 Br CH3 H Cl H CH3 Br Identical constitutional isomers enantiomers diastereomers D. CH3 C H Br Cl Br C Cl H H3C Identical constitutional isomers enantiomers diastereomers Name: _________________________________ 5 7. (24 pts) Give the organic products for the following reactions. Be sure to clearly label the stereochemistry of the products. If possible, label the major and minor products. A. (3 points) Book Problem 6.34c 1) B2H6 in diglyme 2) HOOH, HO- 2-tert-butyl-3,3-dimethyl-1-butene HO B. (3 points each enantiomer, no stereochemistry = no credit) Br2 CH3CH2OH Br OCH2CH3 Br OCH2CH3 + C. (3 points for major product, 3 points for minor product, 1 point for enantiomer, 2 points for major and minor product labels) HI I + I + I MajorMinor D. (3 points) OsO4 HOOH OH OH E. (3 points, no deuterium = no points) NaOCH2CH3 CH3CH2OH, heat CH3 Br DH CH3 D Name: _________________________________ 6 8. (12 pts) Each of the following transformations can be carried out in two or three steps. For each transformation show above and/or below the arrows the necessary reagents and between the arrows show the organic intermediate that is formed in the first reaction and serves as the starting material for the second reaction. (1 point each reagent, 1 point each intermediate) A. Book Problem 6.36e 2-propanol O H2SO4 Δ PhCOOH O CH3COOH Oor B. Book Problem 6.36f isobutyl alcohol tert-butyl alcohol dil. H2SO4H2SO4 Δ (no credit if not dilute or 50% or with H2O) C. CH3 CH3 D D CH3 Br CH3 Br2 hν OCH3 (or any strong base) (Must have both Br2 and light or heat. No credit if Cl2.) D2 Pt (1 point for each reagent)