CHAPTER 1.4 Alcohols, Ethers and Thiols Learning Objective: Learn the nomenclature and uses of Alcohols, Ethers and Thiols. Keywords: Alcohol, Primary Alcohol, Secondary Alcohol, Tertiary Alcohol, Phenol, Thiols, Ether

Alcohols An alcohol contains a hydroxyl group (—OH) attached to a carbon chain. A phenol contains a hydroxyl group (—OH) attached to a benzene ring. water alcohol phenol Copyright © 2005 by Pearson Education, Inc. Publishing as Benjamin Cummings

Naming Alcohols The names of alcohols in IUPAC replace the -e with -ol. with 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

Names the following Alcohols IUPAC names for longer chains - number the chain from the end nearest the -OH group. CH3─CH2─CH2─OH OH │ CH3─CH─CH2─CH3 CH3 OH │ │ CH3─CH─CH2─CH2─CH─CH3 6 5 4 3 2 1

More Names of Alcohols - Answers IUPAC names for longer chains - number the chain from the end nearest the -OH group. CH3─CH2─CH2─OH 1-propanol OH │ CH3─CH─CH2─CH3 2-butanol CH3 OH │ │ CH3─CH─CH2─CH2─CH─CH3 5-methyl-2-hexanol 6 5 4 3 2 1

Some Typical Alcohols | “rubbing alcohol” CH3—CH—CH3 2-propanol (isopropyl alcohol) antifreeze HO—CH2—CH2—OH 1,2-ethanediol (ethylene glycol) glycerol HO—CH2—CH—CH2—OH 1,2,3-propanetriol

End Task Name the following compounds. 1. CH3—CH2—CH2—CH2—OH OH CH3 | | 2. CH3—CH—CH—CH2—CH3 3. 2 minutes End

Solution OH CH3 | | 2. CH3—CH—CH—CH2—CH3 3-methyl-2-pentanol 1. CH3—CH2—CH2—CH2—OH 1-butanol OH CH3 | | 2. CH3—CH—CH—CH2—CH3 3-methyl-2-pentanol 3. cyclopentanol

Phenols in Medicine Phenol is the IUPAC name for benzene with a hydroxyl group. is used in antiseptics and disinfectants. phenol resorcinol or benzenediol 4-hexylresorcinol

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

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. 1 1 3 4 3-chlorophenol 4-bromophenol

End Task Write the structure of each of the following. A. 3-pentanol B. ethyl alcohol C. 4-methylphenol 2 minutes End

Solution Write the structure of the following. A. 3-pentanol OH | CH3—CH2—CH—CH2—CH3 B. ethyl alcohol CH3—CH2—OH C. 4-methylphenol O H C 3

Classification of Alcohols Classification of alcohols is determined by the number of alkyl groups attached to the carbon bonded to the hydroxyl. primary (1°), secondary (2°), or tertiary(3). Primary (1º) Secondary (2º) Tertiary (3º) 1 group 2 groups 3 groups H CH3 CH3 | | | CH3—C—OH CH3—C—OH CH3—C—OH | | | H H CH3

End Task 1) primary, 2) secondary, or 3) tertiary. OH | Classify each alcohol as 1) primary, 2) secondary, or 3) tertiary. OH | A. CH3—CH—CH2—CH3 B. CH3—CH2—CH2—OH C. CH3—CH2—C—CH2—CH3 CH3 2 minutes End

Solution | A. CH3—CH—CH2—CH3 secondary B. CH3—CH2—CH2—OH primary C. CH3—CH2—C—CH2—CH3 tertiary CH3

Thiols Thiols are carbon compounds that contain a –SH group. are named in the IUPAC system by adding thiol to the alkane name of the longest carbon chain. Copyright © 2005 by Pearson Education, Inc. Publishing as Benjamin Cummings

Thiols Thiols often have strong smells. are used to detect gas leaks. are found in onions, oysters, and garlic.

Ethers An ether contains an ─O─ between two carbon groups. has a common name that gives the alkyl names of the attached groups followed by ether. CH3─O─CH3 CH3─CH2─O─CH3 dimethyl ether ethyl methyl ether

End Task Write the structure of the following. A. pentyl propyl ether B. diethyl ether 2 minutes End

Solution A. pentyl propyl ether B. diethyl ether CH3─CH2─O─CH2─CH3

Ethers as Anesthetics Anesthetics inhibit pain signals to the brain. like diethyl ether CH3─CH2─O─CH2─CH3 were used for over a century, but caused nausea and were flammable. developed by the 1960’s were nonflammable. Cl F F Cl F H │ │ │ │ │ │ H─C─C─O─C─H H─C─C─O─C─H F F F H F H Ethane(enflurane) Penthrane

TASK Answer the questions on the handout. If you don’t finish it in class, do it for homework please 