ALCOHOLS, ETHERS, THIOLS

glycols

2 hydroxyl groups w 2 adjacent carbons

alcohol polarity

polar, bc co and oh are polar covalent

how do alcohols associate in liquid state

hydrogen bond

acidity of alcohols

same pKa as water

phenols acidity

weak acids, reacts wit NaOH/strong bases to form water soluble salts

describe dehydration reactions

elimination of h2o from carbon = alkene, happens when alcohol is heated with h2so4 or h3po4

dehydration of primary alcohols

most difficult, requires high temp

dehydration of secondary alcohols

acid catalyzed dehydrations at lower temps

dehydration of tertiary alcohols

acid catalyzed dehydrations at above room temp

what happens when isomeric alkenes are obtained from dehydration

alkene w greater # alkyl groups predominates

oxidation of primary alcohols

becomes aldehyde/carboxylic acid (using potassium dichromate)

oxidation of secondary alcohol

becomes ketone.

tertiary alcohol reactions

resistant to oxidation.

using acid catalyst they are prone to dehydration

ether

oxygen atom bound to 2 carbon atoms

simplest either

dimethyl ether

most common ether

diethyl ether

cyclic ether

one of atoms is oxygen

thiols

contains sulfhydryl group (SH), smelly

common name of thiols

adding word ‘mercaptan’

polarity of thiols

nonpolar covalent, little association of hydrogen bonding, low bp, low solubility

acidity of thiols

weak acid (high pKa)

describe oxidation of thiols

oxidation to disulfides, susceptible to oxidation

important alcohols

ethanol, methanol, isopropyl alcohol, and glycerol, propene (raw material base)

nomenclature of ethers

physical properties of ethers

1. polar

2. weak forces

3. bp close to hydrocarbons of same molecular weight but lower than alcohols with same molecular formula

nomenclature of thiols