Organic Chemistry - Introduction Organic chemistry is the study of carbon compounds. It’s the most versatile element on the table! Animals, plants, and other forms of life consist of organic compounds. Nucleic acids, proteins, fats, carbohydrates, enzymes, vitamins, and hormones are all organic compounds. Copyright © Houghton Mifflin Company. All rights reserved. Intro

Hydrocarbons are the most simple organic compounds. Hydrocarbons contain only carbon (C) and hydrogen. (H) There are two major categories of hydrocarbons Aliphatic (Without Benzene) and Aromatic (With Benzene) Copyright © Houghton Mifflin Company. All rights reserved. Section 14.2

Aliphatic Hydrocarbons Aliphatic hydrocarbons are straight chain hydrocarbons without benzene rings. (Well talk more about those later) Four major divisions: Alkanes Cycloalkanes Alkenes Alkynes Copyright © Houghton Mifflin Company. All rights reserved. Section 14.3

Alkanes are hydrocarbons that contain only single bonds. Alkanes are said to be saturated hydrocarbons The have the maximum number of hydrogen atoms possible. Alkane general formula  CnH(2n + 2) The names of alkanes all end in “-ane.” Copyright © Houghton Mifflin Company. All rights reserved. Section 14.3

Alkanes – What are they good for? Methane = primary component of natural gas Propane & Butane = primary component of bottled gas Gasoline = pentane to decane Kerosene = alkanes with n = 10 to 16 Alkanes with n > 16  diesel fuel, fuel oil, petroleum jelly, paraffin wax, lubricating oil, and asphalt Alkanes are found in paints, plastics, drugs, detergents, insecticides, and cosmetics. Copyright © Houghton Mifflin Company. All rights reserved. Section 14.3

Hydrocarbon Naming System The prefix for an alkane is important. It tells us how many carbons are connected in a chain inside the molecule. 1 Carbon = “Meth” 6 Carbons = “Hex” 2 Carbons = “Eth” 7 Carbons = “Hept” 3 Carbons = “Prop” 8 Carbons = “Oct” 4 Carbons = “But” 9 Carbons = “Non” 5 Carbons = “Pent” 10 Carbons = “Dec” Copyright © Houghton Mifflin Company. All rights reserved.

How to draw an Alkane – 4 ways! Structural formula – a graphical representation of the way atoms are connected Condensed structural formula – save time/space and are convenient. Write like a formula. CH3(CH2)4CH3 Carbon Skeleton formula– Removes the Hydrogens, which are assumed to be there. Line Angle formula– fast to draw. All “bends” and “ends” are carbons. Hydrogen is assumed. Copyright © Houghton Mifflin Company. All rights reserved. Section 14.3

Models of Three Alkanes Structural Formula Condensed Formula Ball and Stick Models Line Formula Copyright © Houghton Mifflin Company. All rights reserved. Section 14.3

#1) Draw the structural formula for propane #1) Draw the structural formula for propane. (Think Lewis Dot w/o the dots) #2) Draw the condensed structural formula for butane. (Think Chemical formulas) Copyright © Houghton Mifflin Company. All rights reserved.

Practice – Naming! #3) Name this Alkane: CH3(CH2)4CH3 Copyright © Houghton Mifflin Company. All rights reserved.

Copyright © Houghton Mifflin Company. All rights reserved. Section 14.3

Isomers Molecules that have the same molecular formula but different structural formulas In the case of many alkanes there is more than one way to arrange the atoms. For example butane and isobutane. Both of these alkanes have the molecular formula of C4H10 but their structural formula and arrangement is quite different. Copyright © Houghton Mifflin Company. All rights reserved. Section 14.3

Butane Isomer of Butane C4H10 Structural Formula Ball-and-Stick Model C4H10 Structural Formula Ball-and-Stick Model Copyright © Houghton Mifflin Company. All rights reserved. Section 14.3

Alkenes and Alkynes Unsaturated Alkenes: carbon-carbon double bonds Molecules that have either double or triple bonds takes away from the maximum number of hydrogen possible. Alkenes: carbon-carbon double bonds Each double bond removes 2 hydrogens Alkynes: carbon-carbon triple bonds. Each triple bond removes 4 hydrogens

General formula is CnH2n “-ane” suffix changes to “-ene” Alkenes Members of the alkene group have a double bond between two carbon atoms. General formula is CnH2n “-ane” suffix changes to “-ene” Said like the letter e Section 14.3

Alkenes When assigning numbers to the chain, the double bond gets priority. Give it the lowest number possible! The number preceding the final name indicates the Carbon atom on which the double bond starts.

General formula is CnH2n-2 Suffix changes to “-yne” Alkynes Members of the alkyne group have a triple bond between two carbon atoms. General formula is CnH2n-2 Suffix changes to “-yne” Said like the word Pine Section 14.3

Naming Alkenes and Alkynes IUPAC nomenclature rules for alkenes and alkynes are similar to alkanes. Step 1. Find the longest chain containing the double or triple bond. This will be the main parent chain. Pick the correct suffix by adding –ene or –yne to the end of the name.

Step 2: Number the carbon so the double or triple bond is the lowest carbon possible. They gets priority over all side chains! The carbon number is based on where the multiple-bond STARTS If the multiple bond is an equal distance from both ends, begin numbering at the end closest to the first branch point.

Step 3: Insert the carbon number where the multiple-bond is located either right before the parent chain name. 2-pentene

Naming Alkenes and Alkynes CH2=CHCH2CH3 1-butene but-1-ene CH3CH=CHCH3 2-butene but-2-ene CH3CCCH3 2-butyne but-2-yne