Chapter 17. Reactions of Organic Functional Groups Part 2. Reactions of Organic Functional Groups Part 2- page 1

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1 Chapter 17 Reactions of rganic Functional Groups art 2 Reactions of rganic Functional Groups art 2- page 1

2 Rxns of rganic Functional Groups art 2: Redox A Closer Look xidation & Reduction Reactions of Inorganic Molecules We ALWAYS know the charge of the following elements & will not use the exceptions. xidation Examples Exceptions umber ure elements 0 The oxidation numbers for each atom in Fe(s) or 2 is zero. none Fixed charge The oxidation number is equal to Alkali metals +1 Alkaline earth metals +2 none metals its charge. Aluminum +3 X in ionic & organic cpds -1 X in CaX 2 is -1. C in CX 4 is -1. none in compounds -2 H in compounds in Mg is -2. in H 2 is H in H 2 is +1. Determine the oxidation number of EACH element in the compounds below. is -1 in peroxides. H is -1 when combined with metals. b 2 a 3 HC 3 - Reactions of rganic Functional Groups art 2- page 2

3 Recognizing Inorganic Redox Rxns 1 / 2 Reactions LY look at the element being oxidized or reduced 2 Steps 1. Assign oxidation numbers to each atom in the reaction. 2. Write the ½ reactions for the elements with changing charges. Cu (s) + H 2(g) Cu (s) + H 2 (g) ½ rxn for hydrogen: ½ rxn for copper: a) Which element is oxidized? b) Which element is reduced? Fe C 2 Fe + 3 C 2 ½ rxn for carbon: ½ rxn for iron: a) Which element is oxidized? b) Which element is reduced? Chemical reactions look at all the compounds in the reaction. Reactions of rganic Functional Groups art 2- page 3

4 xidation & Reduction of rganic Molecules xidation: Gain bonds to xygen Lose bonds to Hydrogen Reduction: Lose bonds to xygen Gain bonds to Hydrogen Classify the following reactions as oxidation or reduction. H H Reactions of rganic Functional Groups art 2- page 4

5 For the reactions below, a) redict the products for the reactions below. Remember: benzene rings are very stable so they will not react. b) Classify each function group. For alcohols, indicate 1, 2, or 3. [H] H [] H [] Example Breathylzer Test (rganic and Inorganic Redox Combined) H + H 2 Cr 2 7 H + Cr 2 3 Reactions of rganic Functional Groups art 2- page 5

6 xidizing Agents: reactant that gets reduced Reducing Agents: reactant that gets oxidized For the following reaction Zn (s) + 2 HCl (aq) Zn 2+ (aq) + H 2(g) + 2 Cl - (aq) a) Write the oxidation half reaction. b) Write the reduction half reaction. c) Which reactant is the oxidizing agent? d) Which reactant is the reducing agent? Reactions of rganic Functional Groups art 2- page 6

7 Reactions of rganic Functional Groups art 3: Redox of RH & Carbonyls xidation of Alcohols Ethanol Metabolism The oxidation of a 1 alcohol Reactions of rganic Functional Groups art 2- page 7

8 Reduction of Carbonyl Groups Use your knowledge of oxidation reactions to complete the reduction pathways in the following diagram. Classify the functional groups (aldehydes, ketones or alcohols) for the alcohols indicate whether they are 1, 2, 3. In biochemical reactions, reduction of carbonyl groups is carried out by AD + or ADH? Reactions of rganic Functional Groups art 2- page 8

Antioxidants ot ALL xidation is Beneficial. xidation reactions form Free Radicals. Antioxidants are substances that trap the odd valence electron to prevent it from causing damage to our biomolecules.

9 Antioxidants ot ALL xidation is Beneficial. xidation reactions form Free Radicals. Antioxidants are substances that trap the odd valence electron to prevent it from causing damage to our biomolecules. xidation from Free Radicals is linked with biological aging. Many antioxidants trap the unpaired electron in an aromatic benzene ring. Vitamin E is an antioxidant. Vitamin E Reactions of rganic Functional Groups art 2- page 9

10 Reactions of rganic Functional Groups art 4: Hydration-Dehydration Hydration-Dehydration Reactions Hydration of Alkenes roduces Alcohols Dehydration of Alcohols roduces Alkenes ractice reactions. a) + H 2 - H 2 b) + H 2 - H 2 c) step 2 in the break down of fatty acids H 2 SCoA Reactions of rganic Functional Groups art 2- page 10

11 Reactions of rganic Functional Groups art 7: Coenzymes & Redox Rxns xidation and Reduction reactions ALWAYS occur together. To oxidize or reduce a biological molecule, we need a second compound that can donate or accept the electrons. Coenzymes are the second compound. Coenzymes: special molecules that shuttle electrons Common xidizing and Reducing Agents xidizing Agents Formula or Rxn Bleach acl xygen 2 Hydrogen peroxide H 2 2 Chromium(VI) Cr 6+ Manganese (VIII) Mn - 4 AD + Coenzyme AD + + 2H + + 2e - ADH + H + FAD Coenzyme FAD + 2[H] FADH 2 ote the difference Reducing Agents Hydrogen H 2 ADH Coenzyme ADH + H + AD + + 2[H] Reactions of rganic Functional Groups art 2- page 11

12 Coenzymes a closer look at the 3 Most Important FAD/FADH 2 FAD is the H Acceptor when C=C (double) bonds form Circle the reactive region of FAD and FADH 2. Diagram the reaction below to indicate the oxidation and reduction ½ reactions. Label each ½ reaction (oxidation or reduction). For the coenzyme, label FAD/FADH 2. H H + + H H Reactions of rganic Functional Groups art 2- page 12

AD + /ADH AD + is the H Acceptor in Most xidations Diagram the reaction below to indicate the oxidation and reduction ½ reactions. Label each ½ reaction (oxidation or reduction).

13 AD + /ADH AD + is the H Acceptor in Most xidations Diagram the reaction below to indicate the oxidation and reduction ½ reactions. Label each ½ reaction (oxidation or reduction). For the coenzyme, label AD + /ADH. H + + H ADH/AD + ADH is the H Donor in Reduction Reactions Diagram the reaction below to indicate the oxidation and reduction ½ reactions. Label each ½ reaction (oxidation or reduction). For the coenzyme, label ADH/AD +. Reactions of rganic Functional Groups art 2- page 13

14 The reactions for two important pairs of coenzymes are shown below. a) ame them: AD +, ADH, FAD, and FADH 2. Hint: Look closely at the chemical structures to find the differences. b) Label each one of the coenzymes as an oxidizing agent or reducing agent. Reaction 1 a) - H H H 2 + H 2 H - H H H H H 2 H H H H H b) Reaction 2 a) H H H H H H H H H H H H H H H 2 H H H H H 2 b) Reactions of rganic Functional Groups art 2- page 14

Oxidation-Reduction Reactions. (Redox) Redox Reactions. Types of Redox Rxn s. Not Redox Reactions. Combustion of methane

Oxidation-Reduction Reactions. (Redox) Redox Reactions. Types of Redox Rxn s. Not Redox Reactions. Combustion of methane Oxidation-Reduction Reactions Redox Reactions Reactions in which one or more electrons are transferred 2Na (s) + Cl 2(g) 2NaCl (s) (Redox) Species loosing electrons is said to be oxidized and the species