15. Which of the following compounds is the oxidant in the reaction below?
(A)
(B)
(C)KOH
(D)oxygen in air
(E)

11. Which of the following compound is the most reactive in an SN1 reaction? (A)(B)(C)(D)(E)

12. Which of the following reaction conditions will give the desire product as shown? Reaction conditions: (1)O3 (2) (3) Excess HBr, then excess KOH (4) BuLi, then H2O (A) (1) and (2) only (B) (2) and (3) only (C) (2), (3) and (4) only (D) All of the above (E) None of the above

13. Which of the following amine CANNOT be synthesized by reductive amination? (A)(B)(C)(D)(E)

14. Which of the following acetal will react the fastest in acid-catalyzed hydrolysis? (A)(B)(C)(D)(E)

16. Rank the reactivity of the following compounds towards nucleophilic substitution of carboxylic acid derivative in increasing order (least to most). (A)2＜3＜5＜1＜4 (B)5＜3＜2＜4＜1 (C)1＜2＜5＜3＜4 (D)1＜2＜3＜5＜4 (E)2＜5＜3＜1＜4

17.Which of the following compound is most likely to be the major product of the following reaction? (A)(B)(C)(D)(E)

18. Which of the following solvent is a protic solvent? (A)(B)(C)(D)(E)

19.Which of the following description about SN2 reaction is incorrect? (A) The rate of the reaction is second order. (B) Inversion of configuration at the reacting center will occur. (C) There is no intermediate in an SN2 reaction. (D) Alkyl fluoride is very reactive in SN2 reaction. (E) In Sx2 reaction, using polar aprotic solvents will give a faster reaction rate compare to polar protic solvents.

20. Which of the following statements is correct? (A) A chiral compound will always react to give a chiral product. (B) The most stable conformation of tert-butylcyclohexane is with the tert-butyI group at the axial position. (C) Aryl amines can be synthesized by reduction of nitroarenes. (D) The Diels-Alder reaction involves rearrangement of electrons between the two HOMOs of the two reactants. (E) A hard nucleophile will prefer to react with an α.β-unsaturated carbonyl compound in 1,4- addition instead of 1,2-addition.

21. Which of the following has the smallest radius? (A)(B)(C)(D)(E) all of the above