1. Hydroboration is a(n) _______________________ reaction. Student Response Correct Answer Feedback A. Reduction B. Elimination C. Oxidation 2. Whic h ac ts at the ac tive reagent in hydroboration? Student Response Correct Answer Feedback A. The alkene B. Tetrahydrofuran C. The monomer (BH3) D. The dimer (B2H6) 3. The net result of the reaction below involves addition of H and OH ac ross a double bond. This hydroboration/oxidation allows the –OH group to add to the least substituted c arbon. What is this type of addition called? Student Response Correct Answer Feedback A. Zaitsev addition B. antiMarkovnikov addition C. anti-Zaitsev addition D. Markovnikov addition General Feedback: Markovnikov’s rule says that “in the addition of HX to an unsymmetrical alkene, the H atom bonds to the less substituted c arbon atom” (Smith, p. 374). In other words, hydrogens go where hydrogens are. This reac tion, however, does just the opposite (see the “Anti-Markovnikov Addition” doc ument available in the Exp 3 folder in this Blac kboard c ourse); this is c alled anti-Markovnikov addition. 4. Whic h of the following structures is the final product of the first step in the following reaction? Student Response A. Structure A B. Structure B C. Structure C D. Structure D Correct Answer Feedback 5. The four-centered transition state of the hydroboration step is shown below. This is a concerted addition reaction meaning all the bonds are being made or broken at the same time. This mec hanism is c harac teristic of a group of reac tions called ____________________ reactions. Student Response Correct Answer Feedback A. Pseudocyc lic B. Pseudoperic yc lic C. Peric yc lic D. Macroc yclic 6. Why are alkylboranes not generally isolated out of solution? Student Response Correct Answer Feedback A. They are pyrophoric B. They are inert C. They will be oxidized D. All of the above 7. Configuration is ________________ in the oxidation step of the above reaction. Student Response A. Retained B. Inverted Correct Answer Feedback 8. Organoboranes have bec ome an attractive pathway for the preparation of which of the following? Student Response Correct Answer Feedback A. Alcohols B. Alkanes C. Amines D. Organohalides E. All of the above 9. Why are highly c oncentrated solutions of hydrogen peroxide dangerous? (Selec t all that apply) Student Response Correct Answer Feedback A. Highly concentrated solutions of peroxides are caustic. B. Highly concentrated solutions of peroxides can be explosive! C. Highly concentrated solutions of peroxides can blister the skin. General Feedback: You should always wear gloves when working with c austic c hemic als such as concentrated hydrogen peroxide. You should always wear safety goggles and lab coats no matter what c hemic als you are working with.