Chapter 13 Alcohols, Phenols, and Thiols

1. Chapter 13 Alcohols, Phenols, and Thiols 13.1Alcohols, Phenols, and Thiols

2. Alcohols and Phenols An alcohol contains • a hydroxyl group (—OH) attached to a carbon chain A phenol contains • a hydroxyl group (—OH) attached to a benzene ring

3. Classification of Alcohols Alcohols are classified • by the number of alkyl groups attached to the carbon bonded to the hydroxyl • as primary (1°), secondary (2°), or tertiary(3)

4. Learning Check Classify each alcohol as P) primary, S) secondary,or T) tertiary. A. B. CH3—CH2—CH2—OH C.

5. Solution A. (S) secondary B. CH3—CH2—CH2—OH (P) primary C. (T) tertiary

6. Guide to Naming Alcohols

7. Naming Alcohols The names of alcohols • in IUPAC system replace -e of alkane name with -ol • that are common names use the name of the alkyl group followed by alcohol Formula IUPAC Common Name CH4 Methane CH3─OH Methanol Methyl alcohol CH3─CH3 Ethane CH3─CH2─OH Ethanol Ethyl alcohol

8. More Names of Alcohols In IUPAC names for longer carbon chains, the chain is numbered from the end nearer the –OH group.

9. Some Typical Alcohols “Rubbing alcohol”: 2-Propanol (isopropyl alcohol) Antifreeze: 1,2-Ethanediol (ethylene glycol) Glycerol: 1,2,3-Propanetriol

10. Learning Check Give the IUPAC name for each of the following: A. CH3—CH2—CH2—CH2—OH B. C.

11. Solution A. CH3—CH2—CH2—CH2—OH 1-butanol STEP 1 Name the longest chain attached to OH: butanol STEP 2Number the chain from the end closer to OH: CH3—CH2—CH2—CH2—OH 4 3 2 1 STEP 3 Name alcohol: 1-butanol

12. Solution (continued) B. 3-methyl-2-pentanol STEP 1 Name the longest chain attached to OH: pentanol STEP 2Number the chain from the end closer to OH: 1 2 3 4 5 STEP 3 Name alcohol and any substituents: 3-methyl-2-pentanol

13. Solution (continued) C. cyclopentanol STEP 1 Name the longest chain attached to OH: cyclopentanol STEP 2Number the chain from the end closer to OH: (not necessary with one substituent) STEP 3 No substituents other than alcohol STEP 4 Name a cyclic alcohol as cycloalkanol: cyclopentanol

14. Learning Check Draw the condensed structural formula of the following: A. 3-Pentanol B. Propyl alcohol C. 3-Methylcyclohexanol

15. Solution Draw the condensed structural formula of the following: A. 3-Pentanol: B. Propyl alcohol: CH3 —CH2 —CH2 —OH C. 3-Methylcyclohexanol:

16. Phenols in Medicine Phenol • is the IUPAC name for benzene with a hydroxyl group • is used in antiseptics and disinfectants Phenol Resorcinol 4-Hexylresoricinol

17. Naming Phenols To name a phenol with two substituents, • assign C-1 to the carbon attached to the –OH • number the ring to give the lowest numbers • use prefixes o, m, and p for common names Phenol 3-chlorophenol 4-bromophenol (m-chlorophenol) (p-bromophenol)

18. Derivatives of Phenol • Compounds of phenol are the active ingredients in the essential oils of cloves, vanilla, nutmeg, and mint.

19. Learning Check Draw the condensed structural formula of the following: A. 3-Pentanol B. Ethyl alcohol C. p-Methylphenol

20. Solution Draw the condensed structural formula of the following: A. 3-Pentanol: B. Ethyl alcohol: CH3—CH2—OH C. p-Methylphenol:

21. Thiols Thiols • are organic compounds that contain a –SH group • are named in the IUPAC system by adding thiol to the alkane name of the longest carbon chain

22. Naming Thiols • In thiols with long carbon chains, the chain is numbered to locate the SH group.

23. Sources of Thiols Thiols • often have strong odors • are used to detect gas leaks • are found in onions, oysters, and garlic

24. Learning Check Draw the condensed structural formula of each of the following compounds: A. 2-Butanethiol B. 2-Methyl-1-butanol

25. Solution Draw the condensed structural formula of each of the following compounds: A. 2-Butanethiol: B. 2-Methyl-1-butanol:

26. Learning Check Name each of the following compounds:

27. Solution Name each of the following compounds: 2-Butanol 3-Methyl-1-pentanol 1-Propanethiol