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
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 CH, CH2 CH2CH2 CH3 OHOH OH OH 1.2-ethanediol 1, 2-propanediol ethylene glycol propylene glycol Chapter 10 12
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 CI 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
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 H H ↑=1.69D C、=0.08D CH2CH3 H3C CH3 ethanol. Mw 46 propane, MW 44 bp78°C bp -42C O、+A=1.30D H3C CH dimethyl ether, MW 46 bp-25°C > Chapter 10 15
Chapter 10 15 Boiling Points =>