the least stable): HN SECTION II REACTIONS AND MECHANISMS(2 points each) 1.NaNHz NHg(Liq) 19. 2.CHaBr HO OH HIO 20.H0 OH B 1.HNO3.H2SO4 Br 2.Fe/HCI 3.NaNOz.HCI.H2O.0C 21. 4.CuCN Na2Cr2O7 22. -CH H,SO4 HaO Heat 1 BHs,THF 2H202.OH H2S04 Heat OH (CHa)2CHCOOH 1.LiALH 1.PBr3 2.H20 2.KCN,DMSO 3.HgO*.heat 1 NaOH SH 2 CHal 26. 1.K2Cr204,H2S04,H20 H OH 2.CHgCH2MgBr,ether 3.H0 27 28.Write a complete mechanism for the substitution (only)reaction shown below. 第5页共6页第 5 页 共 6 页 the least stable): H2 N H2 N SECTION II REACTIONS AND MECHANISMS(2 points each) 19. 2. CH3Br 1. NaNH2 NH3(Liq) 20. OH HO OH HO HIO4 21. Br Br 1. HNO3, H2SO4 2. Fe/HCl 3. NaNO2, HCl, H2O, 00 C 4. CuCN 22. CH3 Na2Cr2O7 H2SO4 H2O Heat 23. 1 B H 3 , T H F 2 H 2 O 2 , O H - 24. OH H2SO4 Heat 25. (CH3)2CHCOOH 1. LiALH4 2. H2O 1. PBr3 2.KCN, DMSO 3. H3O+ , heat 26. S H 1 N a O H 2 C H 3 I 27. OH H 3. H3O+ 2. CH3CH2MgBr, ether 1. K2Cr2O4, H2SO4, H2O 28. Write a complete mechanism for the substitution (only) reaction shown below