1. An Introduction to Organic Compounds
Nomenclature, Physical Properties, and Representation of Structure

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

3. Counting to Ten in Organic
01 = meth Mother
02 = eth Enjoys
03 = prop Peanut
04 = but BUTter
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

4. Alkanes

5. 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.

6. Nomenclature of Alkyl Substituents
There are four alkyl groups that contain four carbons

7. Nomenclature of Alkyl Substituents
The prefix sec- occurs only in sec-butyl

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

9. 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

10. 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.

11. 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

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

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

14. 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

15. Nomenclature of Cycloalkanes
Cycloalkanes generally are shown as skeletal structures

16. 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

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

18. 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

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

20. Nomenclature of Alkyl Halides
IUPAC name - The halogen is treated as a substituent

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

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

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

24. 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

25. 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

26. 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

27. IUPAC Nomenclature of Alcohols
System is summarized as [Substituent] [Parent Hydrocarbon] [Functional Group]

28. 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

29. Nomenclature of Amines
IUPAC name - The NH2 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”
1-butanamine
butan-1-amine

30. 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

31. 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

32. Induced Dipole-Induced Dipole Interactions

33. Hydrogen Bonding: Strong Dipole-Dipole Interactions

34. Dipole-dipole Interactions
Particularly important for ethers vs. alkanes
Ethers and alkyl halides have dipole moments, but their intermolecular attractions are not as strong as hydrogen bonds

35. Comparative Boiling Points

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

37. 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

38. Conformations of Alkanes: Rotation About C-C Single Bonds

39. Chair Conformation of Cyclohexane

40. Drawing Cyclohexane in the Chair Conformation

41. 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

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

43. Conformations of 1,4-Disubstituted Cyclohexanes
trans-1,4-dimethylcyclohexane
two methyl groups on opposite sides of ring
cis-1,4-dimethylcyclohexane
two methyl groups on same side of ring

44. 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

45. 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 stable
much less stable

46. 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 stable
much less stable

47. 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