1. IUPAC Nomenclature of Unbranched Alkanes

2. Retained: methaneCH 4 ethaneCH 3 CH 3 propaneCH 3 CH 2 CH 3 butaneCH 3 CH 2 CH 2 CH 3 IUPAC Names of Unbranched Alkanes

3. Note: n-prefix is not part of IUPAC name of any alkane. For example: n-butane is "common name" for CH 3 CH 2 CH 2 CH 3 ; butane is "IUPAC name." Others: Latin or Greek prefix for number of carbons + ane suffix IUPAC Names of Unbranched Alkanes

4. Number of carbons NameStructure 5pentaneCH 3 (CH 2 ) 3 CH 3 6hexaneCH 3 (CH 2 ) 4 CH 3 7heptaneCH 3 (CH 2 ) 5 CH 3 8octaneCH 3 (CH 2 ) 6 CH 3 9nonaneCH 3 (CH 2 ) 7 CH 3 10decaneCH 3 (CH 2 ) 8 CH 3 IUPAC Names of Unbranched Alkanes

5. Number of carbons NameStructure 11undecaneCH 3 (CH 2 ) 9 CH 3 12dodecaneCH 3 (CH 2 ) 10 CH 3 13tridecaneCH 3 (CH 2 ) 11 CH 3 14tetradecaneCH 3 (CH 2 ) 12 CH 3 15pentadecaneCH 3 (CH 2 ) 7 CH 3 16hexadecaneCH 3 (CH 2 ) 8 CH 3 IUPAC Names of Unbranched Alkanes

6. Number of carbons NameStructure 17heptadecaneCH 3 (CH 2 ) 15 CH 3 18octadecaneCH 3 (CH 2 ) 16 CH 3 19nonadecaneCH 3 (CH 2 ) 17 CH 3 20icosaneCH 3 (CH 2 ) 18 CH 3 25pentacosaneCH 3 (CH 2 ) 22 CH 3 30triacontaneCH 3 (CH 2 ) 28 CH 3 IUPAC Names of Unbranched Alkanes

7. Applying the IUPAC Rules: The Names of the C 6 H 14 Isomers

8. CH 3 CH 2 CH 2 CH 2 CH 2 CH 3 (CH 3 ) 2 CHCH 2 CH 2 CH 3 (CH 3 CH 2 ) 2 CHCH 3 (CH 3 ) 2 CHCH(CH 3 ) 2 (CH 3 ) 3 CCH 2 CH 3 The C 6 H 14 Isomers

9. CH 3 CH 2 CH 2 CH 2 CH 2 CH 3 The IUPAC name of the unbranched alkane with a chain of 6 carbons is hexane. Hexane The C 6 H 14 Isomers

10. Step 1) Find the longest continuous carbon chain and use the IUPAC name of the unbranched alkane as the basis. Step 2) Add name of substituent as a prefix. Step 3) Number the chain from the end nearest the substituent, and identify the carbon to which the substituent is attached by number. IUPAC Nomenclature of Branched

11. (CH 3 ) 2 CHCH 2 CH 2 CH 3 (CH 3 CH 2 ) 2 CHCH 3 2-Methylpentane 3-Methylpentane The C 6 H 14 Isomers

12. (CH 3 ) 2 CHCH(CH 3 ) 2 (CH 3 ) 3 CCH 2 CH 3 2,3-Dimethylbutane 2,2-Dimethylbutane Use replicating prefixes (di-, tri-, tetra-, etc.) according to the number of identical substituents attached to the main chain. The C 6 H 14 Isomers

13. Alkyl Groups

14. Methyl and Ethyl Groups Methyl Ethyl C C HHHH H CH 3 CH 2 C HHH CH 3 or or

15. Unbranched Alkyl Groups If potential point of attachment is at the end of the chain, take the IUPAC name of the corresponding unbranched alkane and replace the -ane ending by -yl. R HR

16. Butyl R HR CH 3 CH 2 CH 2 CH 2 C C HHHH H C C HH H H or Unbranched Alkyl Groups

17. Hexyl CH 3 (CH 2 ) 4 CH 2 CH 3 (CH 2 ) 5 CH 2 CH 3 (CH 2 ) 16 CH 2 Heptyl Octadecyl Unbranched Alkyl Groups

18. The C 3 H 7 Alkyl Groups CH 3 CH 2 CH 2 C C H HH H H C H H or and CH 3 CHCH 3 C C H HH H H C H H or

19. CH 3 CH 2 CH 2 C C H HH H H C H H or IUPAC name: Propyl Common name: n-Propyl The C 3 H 7 Alkyl Groups

20. Naming Alkyl Groups (Table 2.8) Step 1:Identify longest continuous chain starting at point of attachment. Step 2: Drop -ane ending from name of unbranched alkane having same number of carbons as longest continuous chain and replace by -yl. Step 3:Identify substituents on longest continuous chain. Step 4:Chain is always numbered starting at point of attachment.

21. IUPAC name: 1-Methylethyl Common name: Isopropyl CH 3 CHCH 3 C C HHHH C H H or H The C 3 H 7 Alkyl Groups

22. CH 3 CH 2 CH 2 C C HHHH H C H H or Classification: Primary alkyl group Alkyl groups are classified according to the degree of substitution at the carbon that bears the point of attachment. A carbon that is directly attached to one other carbon is a primary carbon. The C 3 H 7 Alkyl Groups

23. Classification: Secondary alkyl group Alkyl groups are classified according to the degree of substitution at the carbon that bears the point of attachment. A carbon that is directly attached to two other carbons is a secondary carbon. CH 3 CHCH 3 C C HHHH C H H or H The C 3 H 7 Alkyl Groups

24. IUPAC name: Butyl Common name: n-Butyl Classification: Primary alkyl group CH 3 CH 2 CH 2 CH 2 C C HHHH H C C HH H H or The C 4 H 9 Alkyl Groups

25. IUPAC name: 1-Methylpropyl Common name: sec-Butyl Classification: Secondary alkyl group CH 3 CHCH 2 CH 3 C C H HH H H C C HH H H or12 3 The C 4 H 9 Alkyl Groups

26. IUPAC name: 2-Methylpropyl Common name: Isobutyl Classification: Primary alkyl group 1 2 3 C H CH 2 CH 3 The C 4 H 9 Alkyl Groups

27. IUPAC name: 1,1-Dimethylethyl Common name: tert-Butyl Classification: Tertiary alkyl group 1 2 C CH 3 The C 4 H 9 Alkyl Groups

28. IUPAC Names of Highly Branched Alkanes

29. Branched alkanes Octane

30. 4-Ethyloctane

31. 4-Ethyl-3-methyloctane List substituents in alphabetical order. Branched alkanes

32. 4-Ethyl-3,5-dimethyloctane List substituents in alphabetical order. But don't alphabetize di-, tri-, tetra-, etc. Branched alkanes

33. First Point of Difference Rule The chain is numbered in the direction that gives the lower locant to the substituent at the first point of difference in the names. Don't add locants! 2,2,6,6,7-Pentamethyloctane? 2,3,3,7,7-Pentamethyloctane? What is correct name? 1 2 3 4 5 6 7 8 8 7 6 5 4 3 2 1

34. First Point of Difference Rule The chain is numbered in the direction that gives the lower locant to the substituent at the first point of difference in the names. Don't add locants! 2,2,6,6,7-Pentamethyloctane? What is correct name? 8 7 6 5 4 3 2 1

35. CnH2nCnH2nCnH2nCnH2n Cycloalkane Nomenclature

36. Cycloalkanes Cycloalkanes are alkanes that contain a ring of three or more carbons. Count the number of carbons in the ring, and add the prefix cyclo to the IUPAC name of the unbranched alkane that has that number of carbons. CyclopentaneCyclohexane

37. Ethylcyclopentane Cycloalkanes CH 2 CH 3 Name any alkyl groups on the ring in the usual way.

38. List substituents in alphabetical order and count in the direction that gives the lowest numerical locant at the first point of difference. 3-Ethyl-1,1-dimethylcyclohexane CH 2 CH 3 H3CH3CH3CH3C CH 3 Cycloalkanes