Boiling Points Solubility in Water Solubility decreases as

Boiling Points =>

Solubility in Water Solubility decreases as the size of the alkyl group increases. =>

Methanol • • “Wood alcohol” Industrial production from synthesis gas Common industrial solvent Fuel at Indianapolis 500 – Fire can be extinguished with water – High octane rating – Low emissions – But, lower energy content Invisible flame => –

Ethanol • • Fermentation of sugar and starches in grains 12 -15% alcohol, then yeast cells die. Distillation produces “hard” liquors Azeotrope: 95% ethanol, constant boiling Denatured alcohol used as solvent Gasahol: 10% ethanol in gasoline Toxic dose: 200 m. L ethanol, 100 m. L methanol =>

2 -Propanol • “Rubbing alcohol” • Catalytic hydration of propene =>

Acidity of Alcohols • • p. Ka range: 15. 5 -18. 0 (water: 15. 7) Acidity decreases as alkyl group increases. Halogens increase the acidity. Phenol is 100 million times more acidic than cyclohexanol! =>

Table of Ka Values =>

Formation of Alkoxide Ions React methanol and ethanol with sodium metal (redox reaction). React less acidic alcohols with more reactive potassium. =>

Formation of Phenoxide Ion Phenol reacts with hydroxide ions to form phenoxide ions - no redox is necessary. O O H + p. Ka = 10 OH + HOH p. Ka = 15. 7 =>

(Synthesis (Review • Nucleophilic substitution of OH- on alkyl halide • Hydration of alkenes – water in acid solution (not very effective) – oxymercuration - demercuration – hydroboration - oxidation =>

(Glycols (Review • Syn hydroxylation of alkenes – osmium tetroxide, hydrogen peroxide – cold, dilute, basic potassium permanganate • Anti hydroxylation of alkenes – peroxyacids, hydrolysis =>

Organometallic Reagents • Carbon is bonded to a metal (Mg or Li). • Carbon is nucleophilic (partially negative). • It will attack a partially positive carbon. –C-X –C=O • A new carbon-carbon bond forms. =>

Grignard Reagents • • Formula R-Mg-X (reacts like R: - +Mg. X) Stabilized by anhydrous ether Iodides most reactive May be formed from any halide – primary – secondary – tertiary – vinyl aryl => –

Some Grignard Reagents =>

Organolithium Reagents • Formula R-Li (reacts like R: +Li) • Can be produced from alkyl, vinyl, or aryl halides, just like Grignard reagents. • Ether not necessary, wide variety of solvents can be used. =>

Reaction with Carbonyl • R: - attacks the partially positive carbon in the carbonyl. • The intermediate is an alkoxide ion. • Addition of water or dilute acid protonates the alkoxide to produce an alcohol. =>

Synthesis of 1° Alcohols Grignard + formaldehyde yields a primary alcohol with one additional carbon. =>