1 Ch. 12: Compounds with O and S Chem 20 El Camino College

2 Alcohols, Thiols, Ethers

3 Naming Alcohols Name the longest carbon chain containing the OH group, use the –ol suffix Number the chain to give the OH the lowest number Give the location and name of other substituents in alphabetical order.

4 Name These 1-butanol2-butanol 3-pentanol

5 Name These 3-methyl-2-pentanol 2,2-dimethyl-1-butanol 2-bromo-2-chloro-1-butanol

6 Draw These 3-methyl-2-butanol 2,2-dibromo-1-propanol cyclopentanol

7 Naming Ethers Write the name of each group attached to the O Use alphabetical order If the groups are the same, use the prefix “di” ethyl methyl ether diethyl ether cyclopropyl methyl ether

8 Solubility “Like dissolves like” explains solubility Alkanes are nonpolar they are insoluble in water Ethers are slightly polar ethers with small carbon chains are water soluble ethers with long carbon chains are water insoluble Alcohols are polar alcohols with small/medium C chains are soluble alcohols with large C chains are water insoluble.

9 Give Name: Solubility propane: insoluble in water dimethyl ether: soluble in water dibutyl ether: insoluble in water ethanol: soluble in water 1-hexanol: soluble in water 1-octanol: insoluble in water

10 Aldehyde and Ketone

11 Oxidation Reaction In one kind of oxidation rxn of alcohols, the carbon bearing the OH turns into a C=O group If the C bearing the OH is attached to one other carbon or less, an aldehyde forms If the C bearing the OH is attached to two other carbons, a ketone forms If the C bearing the OH is attached to three other carbons, no reaction happens.

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13 Draw the product: aldehyde, ketone, or NR?

14 Naming Aldehydes Name the longest carbon chain containing the carbonyl (C=O) Use the suffix “al” Name any substituents by numbering the carbonyl carbon as number 1

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16 Name These pentanal2,3-dibromobutanal

17 Naming Ketones Name the longest carbon chain containing the carbonyl (C=O) Use the suffix “one” Number the main chain from the end nearest the carbonyl. Name and number any substituent

18 Name These pentanal 2-pentanone3-pentanone

19 Name These cyclopentanone 3-heptanone 3,3-dichlorobutanone

20 Properties Aldehydes and ketones are slightly polar They tend to have similar bps to ethers of the same molar mass They tend to have much lower bps than alcohols, because alcohols are much more polar Aldehydes and ketones of 5 C atoms or less are soluble in water

21 Chemical Tests In Tollens’ test, an aldehyde is oxidized to a carboxylic acid. Silver also forms. CH 3 CHO + 2 Ag +  2 Ag(s) + CH 3 COOH

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23 Chemical Tests In Benedict’s test, an aldehyde that has an OH group on the next carbon forms a carboxylic acid. Red ppt also forms. RCHO + 2Cu 2+  Cu 2 O(s) + RCOOH

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25 Isomers Isomers are compounds with the same formula, but the atoms are attached differently “Stereoisomers” have the atoms arranged differently in space--they are related as mirror images.

26 Chiral Carbons Chiral carbons are tetrahedral carbons with four different attachments

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