A Crash Course In Organic Chemistry Organic Chem

A Crash Course In Organic Chemistry

Organic Chem Study of organic chemistry and life n Study of organic compounds in life n Study of hydrocarbon compounds in and their uses in life n

Alkanes (Cn. H 2 n+2) Number of Carbons Prefix Structure 1 Methane CH 4 2 Ethane CH 3 3 Propane CH 3 CH 2 CH 3 4 Butane CH 3(CH 2)2 CH 3 5 Pentane CH 3(CH 2)3 CH 3 6 Hexane CH 3(CH 2)4 CH 3 7 Heptane CH 3(CH 2)5 CH 3 8 Octane CH 3(CH 2)6 CH 3 9 Nonane CH 3(CH 2)7 CH 3 10 Decane CH 3(CH 2)8 CH 3 11 Undecane CH 3(CH 2)9 CH 3 12 Dodecane CH 3(CH 2)10 CH 3

Naming Branched Alkanes n n n Find the longest carbon chain and name alkane Number the carbon from the end with nearest substituent (side group) Determine the name of substituent and add –yl; halogens are chloro, fluoro, iodo Put the names in alphabetical order Identify the positions of all substituents in the name by placing the carbon number where the substituent attaches to the parent chain in front of it. Arrange in alphabetical order and list each one

Naming 2, 2, 4 -trimethyl-3 -propylhexane 3 -ethyl-3 -methyl-4, 5 -dipropyloctane 6 -ethyl-4, 5 -dipropylnonane

Naming http: //www. sciencegeek. net/APchemistry/APtaters/alkanes. htm 4 -ethyl-3 -methyl-4 -propyloctane 2, 2, 3 -trimethylpentane 4, 4 -diethyl-2, 3 -dimethylheptane

Reactions of Alkanes 1. Combustion: reaction with O 2 in the 2. presence of sparks Natural gas CH 4(g) + 2 O 2(g) disposable cigarette lighters 2 C 4 H 10(g) + 13 O 2(g) charcoal lighter fluid C 5 H 12(g) + 8 O 2(g) hydrocarbons in gasoline 2 C 8 H 18(l) + 25 O 2(g) CO 2(g) + 2 H 2 O(g) 8 CO 2(g) + 10 H 2 O(g) 5 CO 2(g) + 6 H 2 O(g) 16 CO 2(g) + 18 H 2 O(g)

2. Halogenation: reaction with halogens (I, Br, F, Cl) to form alkyl halides In the presence of light, or at high temperatures, alkanes react with halogens to form alkyl halides: light CH 4(g) + Cl 2(g) CH 3 Cl(g) + HCl(g) light CH 4(g) + Br 2(l) CH 3 Br(g) + HBr(g)

Halogenation n A substitution reaction where H is substituted by a halogen The reactivity of the halogens is F 2>Cl 2>Br 2>I 2 The reaction of halogen with methane or ethane will form on product since the reactivity of all of the hydrogens is exactly the same C 2 H 6 C 2 H 5 -Cl + HCl

Halogenation of propane up to decane generate more than one alkyl halides since the Hs in the alkanes exhibit different reactivities to halogen n The reactivity of the Hs: 3 o >2 o >1 o 1 o- a C bound to one C 2 o- a C bound to two C H o- a C bound to three C 3 CH 3 -C-CH 3 n CH 3 2

Halogenation n n Halogenation of an alkane with more than one type of H will generate more than one alkyl halide called isomers Same chemical formula but different structures CH 3 -CH 2 -CH 3 + Cl 2 ——> 45% CH 3 -CH 2 Cl + 55% CH 3 -CHCl-CH 3 -CH 2 -CH 3 + Br 2 ——> 3% CH 3 -CH 2 Br + 97% CH 3 -CHBr-CH 3 (CH 3)3 CH + Cl 2 ——> 65% (CH 3)3 CCl + 35% (CH 3)2 CHCH 2 Cl

Alkenes (Cn. H 2 n) Number of Carbons Prefix Structure 2 Ethene CH 2=CH 2 3 Propene CH 2=CHCH 3 4 Butene CH 2=CHCH 2 CH 3 5 Pentene CH 2=CH(CH 2)2 CH 3 6 Hexene CH 2=CH(CH 2)3 CH 3 7 Heptene CH 2=CH(CH 2)4 CH 3 8 Octene CH 2=CH(CH 2)5 CH 3 9 Nonene CH 2=CH(CH 2)6 CH 3 10 Decene CH 2=CH(CH 2)7 CH 3 11 Undecene CH 2=CH(CH 2)8 CH 3 12 Dodecene CH 2=CH(CH 2)9 CH 3

Naming Alkenes 1. Name the longest carbon chain that contains the double bond 2. The name for the alkenes ends in ene instead of –ane 3. Number the main chain from the end nearest the double bond. 4. Indicate the position of the double bond with the number of the first unsaturated carbon. 5. Place the number and names of substituents in front of the alkene name. 6. Cyclic alkenes are named as cycloalkenes.

Naming Alkenes 2 -methyl-2 -pentene 3 -methyl-1 -pentene

Reactions of Alkenes REACTANT REACTION EXAMPLE H 2 Hydrogenation CH 2=CH 2 → H-CH 2 -H (catalyzed by metals) H 2 O X 2 HX Kmn. O 4, H 2 O, and OH- Hydration (catalyzed by acid) Halogenation Hydrohalogenation CH 2=CH 2 → H-CH 2 -OH Oxidation CH 2=CH 2 → OH-CH 2 -OH CH 2=CH 2 → Cl-CH 2 -Cl CH 2=CH 2 → Cl-CH 2 -H

Alkynes (Cn. H 2 n-2) Number of Carbons Prefix Structure 2 Ethyne CHΞCH 3 Propyne CHΞCCH 3 4 Butyne CHΞCCH 2 CH 3 5 Pentyne CH ΞC(CH 2)2 CH 3 6 Hexyne CH ΞC(CH 2)3 CH 3 7 Heptyne CH ΞC(CH 2)4 CH 3 8 Octyne CH ΞC(CH 2)5 CH 3 9 Nonyne CH ΞC(CH 2)6 CH 3 10 Decyne CH ΞC(CH 2)7 CH 3 11 Undecyne CH ΞC(CH 2)8 CH 3 12 Dodecyne CH ΞC(CH 2)9 CH 3

Naming Alkynes 1. Name the longest carbon chain that contains the triple bond 2. The name for the alkenes ends in yne instead of –ane 3. Number the main chain from the end nearest the triple bond. 4. Indicate the position of the triple bond with the number of the first unsaturated carbon. 5. Place the number and names of substituents in front of the alkyne name.

Reactions of Alkynes REACTANT REACTION EXAMPLE H 2 Hydrogenation CHΞCH → CH 2=CH 2 (catalyzed by metals) H 2 O X 2 HX Kmn. O 4, H 2 O, and OH- Hydration (catalyzed by acid) Halogenation Hydrohalogenation CHΞCH → CH 2=CH-OH Oxidation CHΞCH → OH-CH=CH-OH CHΞCH → Cl-CH=CH-Cl CHΞCH → Cl-CH=CH 2

Derivatives of Hydrocarbons A functional group is a reactive portion of a molecule that undergoes predictable reactions. n All other organic compounds can be considered to be derivatives of hydrocarbons n

Organic Functional Gps

Organic Compounds Containing Oxygen n Many of the important functional groups in organic compounds contain oxygen n Examples are n alcohols n ethers n aldehydes n ketones n carboxylic acids n esters

Alcohols n An alcohol is a compound obtained by substituting a hydroxyl group (-OH) for a –H atom on a carbon atom of a hydrocarbon group. • Some examples are methanol 2 -propanol

Alcohols n An ether is a compound with an oxygen “bridge” between two alkyl groups. • An example is diethyl ether

n An aldehyde is a compound containing a carbonyl group with at least one H atom attached to it. • An example is ethanal

n A ketone is a compound containing a carbonyl group with two hydrocarbon groups attached to it. • An example is 2 -butanone

n A carboxylic acid is a compound containing the carboxyl group, -COOH. • An example is ethanoic acid

n An ester is a compound formed from a carboxylic acid, RCOOH, and an alcohol, R’OH. • The general structure is

n Most organic bases are amines, which are compounds that are structurally derived by replacing one or more hydrogen atoms of ammonia with hydrocarbon groups. primary amine secondary amine tertiary amine

n Amides are compounds derived from the reaction of ammonia, or of a primary or secondary amine, with a carboxylic acid. • The general formula for a common amide is

Aromatic Compounds § § § ring compounds: bonds alternate between single & double ones (bonds actually resonate) most common is benzene when one hydrogen is replaced: name by placing the name of the substituent first, followed by -benzene when two hydrogens replaced: ortho (o-), meta (m-) or para (p-) used when more hydrogens replaced: use numbering system for positions on the

Benzene benzene naphthalene

Polycyclic Aromatic Hydrocarbons (PAHs) § § § two or more benzene rings fused together, sharing pairs of carbon atoms PNAs: polynuclear aromatic compounds PCBs: Polychlorinated biphenyls PCDDs: Polychlorinated dibenzodioxins PCDFs: Polychlorinated dibenzofurans anthracene

General Anesthetics

Ether and Chloroform n These agents are the anesthetics from hell Have negative side effects n Flammable and very toxic n CH 3 -CH 2 -O-CH 2 -CH 3

Non Halogenated Hydrocarbons n n n all of these will work, and the longer the chain, the higher the potency. However, they have a tendency to produce cardiovascular toxicity. Cyclopropane (U. S. P. ) is the only one still in use, and it is explosive.

Ethers n n n Like hydrocarbons, the longer the chain, the more potent the anesthetic. However, increasing chain length also increases toxicity and reduces induction time. Ethyl ether is seldom used, and divinyl ether is explosive and produces deep anesthesia too quickly. CH 3 -CH 2 -O-CH 2 -CH 3

Halogenated Hydrocarbons-Cl n n Addition of a halogen can reduce or eliminate flammability, and can also increase potency. Depending on the halogen, some of these compounds can cause arrhythmias and/or renal or hepatic toxicity. Compounds containing only bromine are generally not useful. Compounds containing only chlorine are subject to limited use, are toxic, and can cause arrhythmias. The best of the chlorinated agents are ethyl chloride and trichloroethylene

Chlorinated ethylchloride trichloroethylene

Halogenated-F n n Fluorinated hydrocarbons are the most useful of the general anesthetics Were first discovered as offshoots of the nuclear weapons program Addition of a fluorine decreases flammability, boiling point and the incidence of catecholinduced arrhythmias (these increase as the size of the halogen increases, and F is the smallest halogen). The structures of a few representative fluorinated hydrocarbon general anesthetics are shown

Halogenated Chlorinated and Fluorinated (these are inhaled) halothane isoflurane sevoflurane enflurane desflurane

Fluorinated Halothane, USP (Fluothane) - the first fluorinated hydrocarbon to be introduced, is a poor muscle relaxant, and has some toxicity and propensity to cause catechol-induced arrhythmias. n Methoxyflurane (Penthrane) - this analog is somewhat better, but still causes some arrhythmias and other toxicity. It also causes a slow induction period. n Enflurane, U. S. P. (Enthrane) - good anesthetic, but has unsatisfactory analgesia in Stage I. n Isoflurane (Forane) - the best general anesthetic so far, it has no commonly observed ill effects. n

Nitrous Oxide n n This is the least toxic anesthetic It is the least potent anesthetic It causes good analgesia, but is a poor muscle relaxant. It is an NMDA receptor antagonist so prevent transmission of signals between neurons in the brain N 2 O

Barbiturates (IV) n n n Derivatives of barbit acid act as central nervous system depressants, produce a wide spectrum of effects, from mild Barbituric acid sedation to anesthesia Activate the GABA receptor. GABA is the M principal inhibitory neurotransmitter in the et h Na thiopental mammalian Central Nervous System (CNS). oh e Methohexital

Benzodiazepines (IV) n n n Psychoactive drugs Used before certain medical procedures such as endoscopies or dental work and prior to some unpleasant medical procedures in order to induce sedation and amnesia for the procedure Activates the GABA receptor diazepam midazolam lorazepam

Propofol §a short-acting intravenous anesthetic agent §used for the induction of general anesthesia in adult patients and pediatric patients older than 3 years of age §Activates the GABA receptor-inhibits signal transmission in the brain

Etomidate §short acting intravenous anesthetic agent §used for the induction of general anaesthesia and for sedation for short procedures

Ketamine HCl (IV) n n n deriv of phencyclidine acts like a volatile anesthetic agent It is potent, rapid acting and has a short duration Patients older than 16 will often (27%) have wild dreams and hallucinations during emergence, and so only indicated for children less than 16 years old. NMDA receptor antagonist

Local Anesthetics

Local Anesthetics n n n Local anesthetics are agents which prevent transmission of nerve impulses without causing unconsciousness. They act by binding to fast sodium channels from within (in an open state). Local anesthetics can be either ester or amide based.

Local Anesthetics n Have the following general structure: n Aromatic-benzene ring-hydrophobic n Intermediate-amide or ester portion n Amino portion-hydrophyllic

Amino Esters procaine tetracaine chloroprocaine cocaine

Amino Amides bupivicaine cinchocaine prilocaine levobupivicaine lidocaine ropivacaine

Common Local Anesthetics Duration w/o Epi, min Duration W/ Epi, min Cocaine 45 - 2. 8 - Procaine 15 -30 30 -90 7. 1 8. 5 Chloroprocaine 30 -60 - 11. 4 14. 2 120 -240 240 -480 1. 4 - Lidocaine 30 -120 60 -400 4. 5 7 Mepivacaine 30 -120 4. 5 7 Bupivacaine 120 -240 240 -480 2. 5 3. 2 Etidocaine 200 240 -360 4. 2 5. 7 Prilocaine 30 -120 60 -400 5. 7 8. 5 Anesthetic Maximum Dose w/o Epi, Dose W/ Epi, mg/kg Esters Tetracaine Amides