80 likes | 285 Views
Organic Reactions. Several types of organic reactions occur with some organic compounds. Generally,organic reactions occur slower, due to strong bonds in the molecules. Many reactions require a catalyst to lower the activation energy. A. Substitution Reaction.
E N D
Organic Reactions Several types of organic reactions occur with some organic compounds Generally,organic reactions occur slower, due to strong bonds in the molecules Many reactions require a catalyst to lower the activation energy A. Substitution Reaction Halogen gas + saturated hydrocarbon One atom in the halogen gas switches places with one of the hydrogens in the hydrocarbon Br Br H H H | | | H--C--C--C--H | | | H H H Br H Br H Br - Br H H Creates a substituted hydrocarbon and an acid
If a second halogen gas is added, another substitution will occur HBr HCl H Br H | | | H--C--C--C--H | | | H H H H H H | | | H--C--C--C--H | | | H H H H Br H | | | H--C--C--C--Cl | | | H H H + Br2--> + Cl2 --> If we repeat this process 4 times with chlorine and methane, we get + 4 HCl H | H--C--H | H Cl | Cl--C--Cl | Cl + 4 Cl2 Carbon tetrachloride If we take methane and do 2 chlorine substitutions and 2 fluorine substitutions, we get + 2 HCl and 2 HF Cl | F--C--F | Cl H | H--C--H | H + 2 Cl2 +2 F2 Dichloro difluoromethane Freon
B. Addition Reaction open open Halogen + Unsaturated hydrocarbon Because the double and triple bond is so exposed, it will be the first bond broken when a halogen is added H | H--C--C ≡C--H | H H H H | | / H--C--C==C | \ H H When the double bond breaks, we have two open bonding sites H H | | H--C--C C--C--H | | | | H H H H F F F F F F F--F F F F Both of the halogen atoms are added We only have one product!
Special type of addition H H H | | / H--C--C==C | \ H H H H H | | | H--C--C--C--H | | | H H H + H2 --> “Hydrogenation” Helps turn oils into margarine Another Special type of Addition When a triple bond breaks to a double bond, the two gas atoms are added to the same side of the double bond H H | | H--C--C C--C--H | | H H I I I I I I I--I I I I Creates a “cis” configuration
Examples - Perform the following reactions, identify each as addition or substitution, and draw the products H H H | | | H--C--C--C--H | | | H H H H H H | | | H--C--C--C--H | | | Cl H H Substitution reaction A. + Cl2 + HCl H H H | | | H--C--C==C--C--H | | | H H H Cl H Br H | | | | H--C--C--C--C--H | | | | H Br H H H H Br H | | | | H--C--C--C--C--H | | | | H Br H H + Br2 + Cl2 B. addition reaction + HCl H | H-- C ≡C--C--H | H Substitution reaction H H \ | C == C--C--H / | | F F H addition reaction C. + F2 Notice the cis! I I | | H--C--C--H | | I I 2 addition reactions D. H--C ≡C--H + 2 I2
C. Esterification 1. Reaction Organic acid + alcohol --> ester + water H H O | | || H--C--C--C--OH | | H H H H H | | | O--C--C--C--H | | | H H H H H H | | | O--C--C--C--H | | | H H H H H H | | | O--C--C--C--H | | | H H H H H H | | | HO--C--C--C--H | | | H H H H H H | | | HO--C--C--C--H | | | H H H H2O Notice how the OH from the acid is removed This is a type of Dehydration Synthesis Removal of water to create a bond 2. Esters Last group of organic compounds O || --C--O-- Functional Group In a molecular formula, written as COO This will appear in the middle of a formula
H O | || H--C--C-- | H H H O | | || H--C--C--C-- | | H H H H O | | || H--C--C--C-- | | H H H H H | | | O--C--C--C--H | | | H H H H H | | O--C--C--H | | H H H H H | | | O--C--C--C--H | | | H H H Acid side Alcohol side We always write the acid side first C2H5 COO C3H7 3. Naming Esters Named by taking the groups name of the alcohol, then by taking the “oic acid” and changing it to “oate” Examples Ethanol Propanoic acid Ethyl propanoate Propyl ethanoate
H O | || H--C--C-- | H H H H | | | O--C--C--C--H | | | H H H O || H--C-- H H H H | | | | O--C--C--C--C--H | | | | H H H H Examples - Write out the products of the esterification, then write the molecular formula of the ester O || H--C--OH H H H H | | | | HO--C--C--C--C--H | | | | H H H H + H2O Butyl methanoate H H H O | | | H--C--C--C--H | | | H H H O H || | HO--C--C--H | H Propyl ethanoate