49. Which of the following compounds is the most reactive toward electrophilic aromatic substitution
13. Which of the following structures is a Fischer projection of (2R,3R,4S)-2,3,4-tribromoheptane? (
14. Arrange the following substrates in order of their increasing SN2 reactivity with NaCN:(I) 1-bro
15. Both [E]- and (Z)-hex-3-ene can be treated with D2 in the presence of a platinum catalyst. How a
40.A=酸性化合物，B =鹼性化合物，C=中性化合物。。依據以下分離流程圖，請問II=? (A)II=中性化合物(B) II=鹼性化合物(C)II =酸性化合物(D) II =酸性化合物+鹼性化合物
16. Consider the data illustrated below. The formula of unknown compound is C9H9NIR (cm-1): 3050, 29
52. Which of the following compounds has the most signals in the noise-decoupled 13C NMR spectrum?(A
53. Identify the aromatic compounds. (A) I and II (B) II and III (C) I and III (D) III and IV (E) I,
17. In electrophilic aromatic substitution reactions, the hydroxyl group is an o,p-director because:
18. (S)-2-Methylbutanal __________ upon sitting in an acidic or a basic aqueous solution.(A) racemiz
19. When a carbonyl is part of a conjugated π-network, the C=O stretch:(A) has a higher frequency th
20. When pent-1-ene is treated with mercury(II) acetate in methanol and the resulting product is rea
54. Which of the following compounds has the highest melting point?(A) benzene (B) toluene (C) o-dic