page 1 / 10 ORGANIC CHEMISTRY 30B Winter 2012 MIDTERM EXAM II On my honor, I have neither given nor received any aid on this examination NAME KEY (use ink please) LAST FIRST MIDDLE SIGNATURE (use ink please) UCLA id: TA (circle name): Melissa Timothy Byron Problem Points 1 (18) 2 (12) 3 ( 5) 4 ( 5) 5 (10) 6 (20) 7 (10) 8 (10) 9 (10) TOTAL / 100 INSTRUCTIONS: —This a closed book exam. —Only exams written in ink will be considered for regradingpage 2 / 10 PART 1. NOMENCLATURE, PHYSICAL PROPERTIES AND GENERAL CONCEPTS 1. (18 points) Please draw the line-wedge-dashed line structures that correspond to the following names: OOCH3(S)-4-methoxyhexan-2-one2-methylpropanoic acidOOHcyclopentyl-cyclohexyl-etherOtrans-1,4-dimethoxycyclohexaneOOTosyl chlorideSClOOHO(E)-pent-3-enalpage 3 / 10 2) (12 points) Considering the hydrogen atoms shown in boldface, please rank the structures in each of the following sets in order of increasing acidity from 1 to 3 (3 being the most acidic). Please indicate your rankings within each box. s 3. (5 points). As above, please rank the structures in the following set 1 to 4 in order of increasing basicity OHNHSH123OHOHOH231HOOOHOOHCl213Ranking:Ranking:Ranking:1234page 4 / 10 4. (5 points). Carboxylic acids have a high tendency to form self-complementary hydrogen bonded dimers. Within the box, please draw the structure of the dimer formed by cyclopentyl carboxylic acid. 5. (10 points) The following four 13C NMR spectra correspond to the following four isomeric compounds (C6H10O) in no particular order. Please draw the correct structure of the corresponding compound within the box provided. Only the structure within the box provided will be considered for credit. 5,6-epoxi-1-hexene 1,2-epoxycyclohexene di-2-propenyl ether trans-2-hexenal OOHOOHpage 5 / 10page 6 / 10 PART 2. REACTIONS AND REAGENTS In this section, please draw inside the corresponding box the correct structure of the reactans, reagents, or products expected for each of the following reactions. For full credit, please make sure that the stereochemistry is correct. Only the answer inside the box will be graded! (6) (20 points) OH1) NaHBr2)Opage 7 / 10 ClNaS-PrAcetoneS-PrBrCuLi2EtherOHOHOH+ cat-H2OOOpage 8 / 10 (7) (10 points) OCH3Br1) Mgo ether2) CO23) HCl, H2OOCH3CO2HOHCl dil / H2OOHOHOOHPCCCH2Cl2OOH+ catiPrOH+ enantiomerpage 9 / 10 (8) (10 points) (9) (10 points) (end of questions) 1) BH3 . THF2) H2O2, NaOHHO OHOOCH2=PPh3OOO OOOOOHCl cat.HdryOH1) MCPBACH2Cl22) HCl dilute in etherOOH1)