Naming Diols Two numbers are needed to locate the two -OH groups. Use -diol as suffix instead of -ol. HO OH 1,6-hexanediol => Chapter 10 11
Chapter 10 11 Naming Diols • Two numbers are needed to locate the two -OH groups. • Use -diol as suffix instead of -ol. HO OH 1,6-hexanediol =>
Glycols 1,2 diols (vicinal diols)are called glycols. Common names for glycols use the name of the alkene from which they were made. CH2CH2 CH2CH2CH3 OHOH OH OH 1,2-ethanediol 1,2-propanediol ethylene glycol propylene glycol Chapter 10 二72
Chapter 10 12 Glycols • 1, 2 diols (vicinal diols) are called glycols. • Common names for glycols use the name of the alkene from which they were made. CH2 CH2 OH OH CH2 CH2 CH3 OH OH 1,2-ethanediol ethylene glycol 1,2-propanediol propylene glycol =>
Naming Phenols .-OH group is assumed to be on carbon 1. For common names of disubstituted phenols, use ortho-for 1,2;meta-for 1,3;and para-for 1,4. Methyl phenols are cresols. OH OH H3C 4-methylphenol 3-chlorophenol para-cresol => meta-chlorophenol Chapter 10 13
Chapter 10 13 Naming Phenols • -OH group is assumed to be on carbon 1. • For common names of disubstituted phenols, use ortho- for 1,2; meta- for 1,3; and para- for 1,4. • Methyl phenols are cresols. OH Cl 3-chlorophenol meta-chlorophenol OH H3 C 4-methylphenol para-cresol =>
Physical Properties Unusually high boiling points due to hydrogen bonding between molecules. Small alcohols are miscible in water,but solubility decreases as the size of the alkyl group increases. => Chapter 10 14
Chapter 10 14 Physical Properties • Unusually high boiling points due to hydrogen bonding between molecules. • Small alcohols are miscible in water, but solubility decreases as the size of the alkyl group increases. =>
Boiling Points 0 H ↑u=1.69D C u=0.08D H CH,CH, HC CH ethanol,MW 46 propane,MW 44 bp 78C bp-42C 00x 0 ↑=1.30D H.C CH; dimethyl ether,MW 46 bp -25C > Chapter 10 15
Chapter 10 15 Boiling Points =>