Chapter 21 An Introduction to Organic Compounds: Chapter 2 Nomenclature, Physical Properties, and Representation of Structure

Chapter 22 Contents of Chapter 2 Nomenclature Structures of Alkyl Halides, Alcohols, Ethers, and Amines Physical Properties Conformations of Alkanes Cycloalkanes

Chapter 23 Counting to Ten in Organic 01 = methMother 02 = eth Enjoys 03 = prop Peanut 04 = butBUTter 05 = pent PENTagon 06 = hex HEXagon or HEX nut 07 = hept HEPTember (Roman sept is Greek hept) 08 = oct OCTober 09 = non NONember (Roman nov is Greek non) 10 = dec DECember

Chapter 24 Alkanes

Chapter 25 Primary, Secondary, Tertiary A primary carbon has one other C directly bonded to it. A secondary carbon is directly bonded to two other C’s. A tertiary carbon is directly bonded to three other C’s. Multivalent atoms are 1º, 2º, or 3º by bonding to C’s. Univalent atom or group not really 1º, 2º, or 3º on its own - ID depends on type of carbon it is bonded to.

Chapter 26 Nomenclature of Alkyl Substituents There are four alkyl groups that contain four carbons

Chapter 27 Nomenclature of Alkyl Substituents The prefix sec- occurs only in sec-butyl

Chapter 28 Nomenclature of Alkyl Substituents The prefix tert- can be used with butyl or pentyl (also known as amyl) but not with hexyl

Chapter 29 IUPAC Systematic Nomenclature - Alkanes Determine longest continuous chain (i.e. parent hydrocarbon) Cite the name of substituent before the name of the parent hydrocarbon along with the number of the carbon to which it is attached

Chapter 210 IUPAC Systematic Nomenclature - Alkanes Number in the direction that gives the lower number for the lowest-numbered substituent. Substituents are listed in alphabetical order – neglecting prefixes such as di- tri- tert- etc.

Chapter 211 IUPAC Systematic Nomenclature - Alkanes When both directions yield the same lower number for the lowest numbered substituent, select the direction that yields the lower number for the next lowest numbered substituent

Chapter 212 IUPAC Systematic Nomenclature - Alkanes If same substituent numbers are obtained in either direction, number in direction giving lowest number to the first named substituent

Chapter 213 IUPAC Systematic Nomenclature - Alkanes If compound has two or more chains of the same length, parent hydrocarbon is chain with greatest number of substituents

Chapter 214 IUPAC Systematic Nomenclature - Alkanes Names such as sec-butyl and tert-butyl are acceptable, but systematic substituent names are preferable Numbering of the substituent begins with the carbon attached to the parent hydrocarbon This number together with the substituent name is placed inside parentheses

Chapter 215 Nomenclature of Cycloalkanes Cycloalkanes generally are shown as skeletal structures

Chapter 216 Nomenclature of Cycloalkanes Ring is the parent hydrocarbon unless the alkyl substituent has more carbons; in that case the substituent becomes the parent hydrocarbon If only one substituent, no need to give it a number

Chapter 217 Nomenclature of Cycloalkanes If the ring has 2 substituents, list in alphabetical order and give number 1 to first named group

Chapter 218 Nomenclature of Cycloalkanes If there is more than one substituent, list in alphabetical order; one substituent is given the position number 1; number either clockwise or counterclockwise - lowest numbers

Chapter 219 Nomenclature of Alkyl Halides Common name - Name the alkyl group first, followed by the name of the halogen expressed as an -ide name

Chapter 220 Nomenclature of Alkyl Halides IUPAC name - The halogen is treated as a substituent

Chapter 221 Nomenclature of Ethers Common name - Name(s) of alkyl group(s) listed first followed by the word “ether”

Chapter 222 Nomenclature of Ethers IUPAC name - The smaller alkyl group is converted to an “alkoxy” name and used as a substituent

Chapter 223 Nomenclature of Alcohols Common name - Name of the Alkyl group followed by the word “alcohol”

Chapter 224 Nomenclature of Alcohols IUPAC name - The OH group is a site of reactivity (a functional group) Functional group is denoted by the suffix, “ol” methanol ethanol

Chapter 225 IUPAC Nomenclature of Alcohols Parent Hydrocarbon is the longest continuous chain that contains the OH Number the chain in direction that gives functional group the lowest number If both a substituent and a functional group are present, the functional group gets the lower number

Chapter 226 IUPAC Nomenclature of Alcohols If the functional group gets the same number when counted from both directions, use direction which gives the substituent the lower number If there is more than one substituent, cite substituents in alphabetical order

Chapter 227 IUPAC Nomenclature of Alcohols System is summarized as [Substituent] [Parent Hydrocarbon] [Functional Group]

Chapter 228 Nomenclature of Amines Common name - Name of the Alkyl group(s) (in alphabetical order) followed by the syllable “amine” The whole name is a single word methylamine methylpropylamine

Chapter 229 Nomenclature of Amines IUPAC name - The NH 2 group is a site of reactivity (a functional group) Functional group is denoted by the suffix, “amine” Final “e” of longest alkane group replaced by suffix “amine” (don’t run vowels together) 1-butanamine butan-1-amine

Chapter 230 IUPAC Nomenclature of Amines Find the longest chain bonded to the nitrogen Final “e” is replaced with “amine” Number the carbon to which nitrogen is bonded Number any substituents on the alkyl chain Use italicized N- for each additional substituent(s) on the nitrogen

Chapter 231 Properties of Alkyl Halides, Alcohols, Ethers, & Amines For alkanes, there are only induced dipole-induced dipole interactions (also known as van der Waals forces or London forces) van der Waals forces are a function of surface area

Chapter 232 Induced Dipole-Induced Dipole Interactions

Chapter 233 Hydrogen Bonding: Strong Dipole-Dipole Interactions

Chapter 234 Dipole-dipole Interactions Particularly important for alcohols and amines Ethers and alkyl halides have dipole moments, but their intermolecular attractions are not as strong as hydrogen bonds

Chapter 235 Comparative Boiling Points

Chapter 236 Solubility The more carbons that are present, the less soluble an organic compound is in water

Chapter 237 Newman Projections A convenient way to describe conformation isomers is to look at the molecule along the axis of the bond of interest A Newman projection is a graphical representation of such a view

Chapter 238 Conformations of Alkanes: Rotation About C-C Single Bonds

Chapter 239 Chair Conformation of Cyclohexane

Chapter 240 Drawing Cyclohexane in the Chair Conformation

Chapter 241 Interconversion of Cyclohexane Conformations As a result of simultaneous rotation about all C-C bonds, a chair conformation of cyclohexane can interconvert to another chair conformation by a ring-flip In the process, equatorial bonds become axial and vice versa

Chapter 242 Monosubstituted Cyclohexanes When there is one substituent on the cyclohexane ring, the two chair conformations are no longer equivalent

Chapter 243 Conformations of 1,4- Disubstituted Cyclohexanes cis-1,4-dimethylcyclohexanetrans-1,4-dimethylcyclohexane two methyl groups on same side of ring two methyl groups on opposite sides of ring

Chapter 244 Conformations of 1,4- Disubstituted Cyclohexanes The cis isomer must have one substituent in an axial position and one in an equatorial position cis-1,4-dimethylcyclohexane ring-flip axial equatorial axial

Chapter 245 Conformations of 1,4- Disubstituted Cyclohexanes The trans isomer has both substituents in either the equatorial or in the axial positions trans-1,4-dimethylcyclohexane ring-flip equatorial axial much more stablemuch less stable

Chapter 246 Conformations of cis-1,3- Disubstituted Cyclohexanes A cis-1,3-disubstituted cyclohexane can exist in one of two conformations cis-1-tert-butyl-3-methylcyclohexane ring-flip much more stablemuch less stable

Chapter 247 Conformations of trans-1,3- Disubstituted Cyclohexanes Both conformers of trans-1-tert-butyl-3- methylcyclohexane have one substituent in an axial position and one in an equatorial position