1. Lecture: 4 Introduction about Functional Groups
Dr. A.K.M. Shafiqul Islam

2. Alkanes

3. Constitutional isomers with the formula of C5H12.
Butane and isobutane are constitutional isomers with the formula of C4H10. The “iso”prefix is two CH3 attached to a CH.

4. Constitutional isomers with the formula of C5H12.
Pentane, isopentane, and 2,2-dimethylpropane are constitutional isomers with the formula of C5H12.

5. Five constitutional isomers with the formula of C6H14.
The constitutional isomers with the formula of C6H14 are n-hexane, isohexane, 2,2-dimethylbutane, 3-methylpentane, and 2,3-dimethylbutane.

6. Nine constitutional isomers with the formula of C7H16.
The constitutional isomers with the formula of C7H16 are n-heptane, 2-methylhexane, 3-methylhexane, 2,3-dimethylpentane, 2,4-dimethylpentane, 2,2-dimethylpentane, 3,3-dimethylpentane, 3-ethylpentane, and 2,2,3-trimethylbutane.

7. Alkyl substituents for the first five alkyl groups.
Alkyl substituents for the first five hydrocarbons are methyl, ethyl, propyl, butyl, and pentyl.

8. Alkyl substituents for the first five alkyl groups
Alkyl substituents for the first five hydrocarbons are methyl, ethyl, propyl, butyl, and pentyl.

9. General structures for an alcohol, an amine, an alkyl halide, and an ether.
An alcohol is an OH group, an amine is an NH2 group, an alkyl halide has one of the halogens as a substituent and an ether is an oxygen placed between two carbons.

10. Common names of functional groups
The alkyl group followed by the name of the class of the compound yields the common name of the compound

11. Ball-and-stick structures of methyl alcohol, methyl chloride, and methyl amine
The common names are named with the alkyl group first, followed by the class of the compound

12. Primary and secondary carbons definition
A primary carbon is attached to one carbon. A secondary carbon is attached to two carbons

13. Ball-and-stick structures of isopropyl chloride
Two structures may have the same name, but just look differently

14. Primary, secondary, and tertiary carbons
A primary carbon has one other carbon attached to it. A secondary carbon has two other carbons attached to it. A tertiary carbon has three other carbons attached to it

15. Primary, secondary, and tertiary hydrogens
A primary hydrogen is attached to a primary carbon. A secondary hydrogen is attached to a secondary carbon. A tertiary hydrogen is attached to a tertiary carbon

16. "Sec" prefix in common names
"Sec" means that the functional group is attached to the secondary carbon. "Sec" cannot be used for groups larger than butyl.

17. "Tert" prefix in common names
"Tert" means that the functional group is attached to a tertiary carbon, which is attached to three other carbons. "Tert" is used for butyl and pentyl groups only

18. Names of Some Common Alkyl Groups
"Iso" is used for two CH3 attached to a CH and the functional group is attached to the other end. "Sec" means that the functional group is attached to a secondary carbon. "Tert" means that the functional group is attached to a tertiary carbon

19. Examples of "iso" in common nomenclature
If "iso" is used, the compound contains two CH3 on a CH on one end of the structure and the functional group on the other end of the structure

20. Finding the parent chain
Shown are three different alkanes that both have 8 carbons in the longest parent chain. The parent chain then becomes octane for all of the structures.

21. Numbering of carbon chains
The longest chain is always numbered such that the substituents have the lowest possible number. The substituent and the parent chain are then placed as one word preceded by the position number of the substituent

22. Common vs. systematic name
Only systematic names have numbers; common names never have numbers.

23. Numbering the chain in IUPAC nomenclature
Number the chain so that the lowest possible combinations of numbers are used. The groups are listed in alphabetical order

24. Multiple identical groups in IUPAC nomenclature
When there is more than one of the same substituent the prefix of di, tri, etc. is used in front of the substituent's name to indicate their number. Then each substituent receives a number in front, separated by a comma

25. Multiple identical groups in IUPAC nomenclature
When there is more than one of the same substituent the prefix of di, tri, etc. is used in front of the substituent's name to indicate their number. Then each substituent receives a number in front, separated by a comma

26. Numbering the chain in systematic naming
Number the chain so that the lowest possible combinations of numbers are used for the substituents

27. If the same substituent numbers are obtained in both directions, the first group cited receives the lowest number
The substituents are listed in alphabetical order

28. If a compound has two or more chains of the same length, the parent hydrocarbon is the chain with the greatest number of substituents
The name on the left has two substituents. The name on the right has one substituent

29. Names such as "isopropyl," "sec-butyl," and "tert-butyl" are acceptable substituent names in the IUPAC system of nomenclature, but systematic substituent names are preferred
Systematic substituent names are obtained by numbering the alkyl substituent starting at the carbon attached to the parent hydrocarbon

30. Some substituents only have a systematic name
Number the longest continuous chain. Number the substituents so that the lowest possible combination of numbers are used

31. Structures of cycloalkanes
Structures of cyclopropane, cyclobutane, cyclopentane, and cyclohexane

32. Skeletal structures of cycloalkanes
Skeletal structures of the cyclopropane, cyclobutane, cyclopentane, and cyclohexane

33. Skeletal structures of alkanes
Skeletal structures of noncyclic alkanes

34. In a cycloalkane with an attached alkyl substituent, the ring is the parent hydrocarbon unless the substituent has more carbon atoms than the ring. In that case, the substituent is the parent hydrocarbon and the ring is named as the substituent
There is no need to number the position of a single substituent on the ring

35. If the ring has two different substituents, they are cited in alphabetical order and the number 1 position is given to the substituent cited first
The ring is numbered so that the lowest possible numbers are used

36. If there are more than two substituents, the groups are listed in alphabetical order. The ring is numbered so that the lowest possible combination of numbers are used
All substituents have numbers

37. Classification of alkyl halides
A primary halide has a halogen attached to a primary carbon; a secondary alkyl halide has a halogen bonded to a secondary carbon; and a tertiary halide has a halogen attached to a tertiary carbon

38. Common and systematic names for alkyl halides
The common name uses alkyl substituents followed by the name of the halide. No numbers are used for common names

39. Nomenclature of alkyl halides
The longest continous chain or ring is the parent name. Number from whichever end that gives the lowest possible combination of numbers for the substituents

40. An ether is a compound in which an oxygen is bonded to two alkyl substituents
If the alkyl substituents are identical, the ether is a symmetrical ether. If the substituents are different, the ether is an unsymmetrical ether

41. The common name of an ether consists of the names of the two alkyl substituents, followed by the word "ether."
The smallest ethers are almost always named by their common names

42. Common nomenclature of symmetrical ethers
The prefix "di" is used for naming symmetrical ethers

43. The IUPAC system names an ether as alkane with an RO substituent
The IUPAC system names an ether as alkane with an RO substituent. The substituents are named by replacing the "yl" ending in the name of the alkyl substituent with "oxy.“
The longest R group is the parent compound

44. Classification of alcohols
A primary alcohol has an OH attached to a primary carbon. A secondary alcohol has an OH attached to a secondary carbon. A tertiary alcohol has an OH attached to a tertiary carbon

45. Common nomenclature of alcohols
Alcohols are named by changing the "ane" ending on the alkane to "yl" and adding alcohol

46. Common nomenclature of alcohols
The common name of an alcohol consists of the name of the alkyl group to which the OH group is attached, followed by the word "alcohol."

47. Systematic names of alcohols
The systematic name of the alcohol is obtained by replacing "e" at the end of the name of the parent hydrocarbon with the suffix "ol." Number the chain from whichever end that gives the OH the lowest possible number

48. IUPAC nomenclature of alcohols
The position of the functional group is indicated by a number immediately preceding the name of the alcohol or immediately preceding the suffix

49. IUPAC nomenclature of alcohols
The parent hydrocarbon is the longest continuous chain containing the functional group. The parent hydrocarbon is numbered in the direction that gives the functional group suffix the lowest possible number

50. If there is a functional group suffix and a substituent, the functional group suffix gets the lowest possible number
Always circle the parent chain first

51. If counting in either direction gives the same number for the functional group suffix, the chain is numbered in the direction that gives a substituent the lowest possible number
A number is not needed to designate the position of a functional group's suffix in a cyclic compound, because it is assumed to be position 1.

52. If there is more than one substituent, the substituents are cited in alphabetical order
The name of the substituent is named before the parent hydrocarbon. The functional group is stated after the parent hydrocarbon.