1. AlcoholsR-O-H Classification CH 3, 1 o, 2 o, 3 o Nomenclature: Common names: “alkyl alcohol” IUPAC: parent = longest continuous carbon chain containing the –OH group. alkane drop -e, add –ol prefix locant for –OH (lower number for OH)

2. CH 3 CH 3 CH 3 CHCH 2 CHCH 3 CH 3 CCH 3 OH OH 4-methyl-2-pentanoltert-butyl alcohol 2-methyl-2-propanol 2 o 3 o CH 3 HO-CHCH 2 CH 3 CH 3 CH 2 CH 2 -OH sec-butyl alcoholn-propyl alcohol 2-butanol 1-propanol 2 o 1 o

3. Physical properties of alcohols: polar + hydrogen bonding relatively higher mp/bp water insoluble! (except for alcohols of three carbons or less) CH 3 CH 2 CH 2 CH 2 CH 2 CH 2 CH 2 CH 2 CH 2 CH 2 -OH hydrophobic hydrophilic

4. Oldest known organic synthesis: “fermentation” Sugar + yeast  ethyl alcohol + CO 2 Grape juice => “wine” Barley => “beer” Honey => “mead” Rice => “sake” ~5-11% ethanol

5. Distillation of fermented beverages to produce “distilled spirits” with a greater percentage of ethyl alcohol (bp 78.3 o C). Ethyl alcohol forms a binary azeotrope with water: 95% ethanol + 5% water (bp 78.15 o C) Diluted with water => “vodka” 40% ethyl alcohol in water. “proof”: when aqueous alcohol is placed on a sample of gunpowder and ignited, the gunpowder will burn at a minimum concentration of 50% alcohol. This is called “100-proof”. (proof = 2 * alcohol percent)

6. Add oil of juniper => gin Add peat smoke => scotch Age in a burned barrel => whiskey Add peppermint => schnapps Etc. Ethyl alcohol is a poison. LD 50 = ~10g/Kg orally in mice. Nausea, vomiting, flushing, mental excitement or depression, drowsiness, impaired perception, loss of coordination, stupor, coma, death may occur. (intoxication)

7. Alcohols, synthesis: 1. 2. 3. 4. Hydrolysis of alkyl halides (CH 3 or 1 o ) 5. 6. 7. 8.

8. NR   some NR  1 o /2 o NR  R-H R-X R-OH Acids Bases Active metals Oxidation Reduction Halogens

9. Alcohols, reactions: R-|-OH 1.With HX 2.With PX 3 3.(later) RO-|-H 4.As acids 5.Ester formation 6.Oxidation

10. 1. Reaction of alcohols with HX: (#1 synthesis of RX) R-OH + HX  R-X + H 2 O a) HX: HI > HBr > HCl b) ROH: 3 o > 2 o > CH 3 > 1 o c) May be acid catalyzed d) Rearrangements are possible except with most 1 o alcohols.

11. CH 3 CH 2 CH 2 CH 2 -OH + NaBr, H 2 SO 4, heat  CH 3 CH 2 CH 2 CH 2 -Br n-butyl alcohol n-butyl bromide 1-butanol 1-bromobutane CH 3 CH 3 CH 3 C-OH + HCl  CH 3 C-Cl (room temperature) CH 3 CH 3 tert-butyl alcoholtert-butyl chloride 2-methyl-2-propanol2-chloro-2-methylpropane CH 3 CH 2 -OH + HI, H +, heat  CH 3 CH 2 -I ethyl alcohol ethyl iodide ethanol iodoethane

12. Mechanism? CH 3 -OH and most 1 o alcohols react with HX via S N 2 mechanism 3 o and 2 o react with HX via S N 1 mechanism  Both mechanisms include an additional, first step, protonation of the alcohol oxygen: R-OH + H +  R-OH 2 + “oxonium ion”

13. Whenever an oxygen containing compound is placed into an acidic solution, the oxygen will be protonated, forming an oxonium ion.

14. Mechanism for reaction of an alcohol with HX: CH 3 OH or 1 o alcohols:

15. Mechanism for reaction of an alcohol with HX: 2 o or 3 o alcohols:

16. May be catalyzed by acid. S N 2 rate = k [ ROH 2 + ] [ X - ] S N 1 rate = k [ ROH 2 + ] Acid protonates the -OH, converting it into a better leaving group (H 2 O), increasing the concentration of the oxonium ion, and increasing the rate of the reaction.

17. Rearrangements are possible (except with most 1 o alcohols): CH 3 CH 3 CH 3 CHCHCH 3 + HBr  CH 3 CCH 2 CH 3 OH Br   Br - CH 3 CH 3 [1,2-H] CH 3 CH 3 CHCHCH 3  CH 3 CHCHCH 3  CH 3 CCH 2 CH 3 OH 2 + + + 2 o carbocation 3 o carbocation

19. Most 1 o ? If large steric requirement… CH 3 CH 3 CH 3 CCH 2 -OH + HBr  CH 3 CCH 2 CH 3 CH 3 Br neopentyl alcohol 2-bromo-2-methylbutane   CH 3 CH 3 CH 3 CH 3 CCH 2 -OH 2 +  CH 3 CCH 2 +  CH 3 CCH 2 CH 3 CH 3 CH 3 + 1 o carbocation 3 o carbocation [1,2-CH 3 ]

20. 2.With PX 3 ROH + PX 3  RX a)PX 3 = PCl 3, PBr 3, P + I 2 b)No rearrangements c)ROH: CH 3 > 1 o > 2 o CH 3 CH 3 CH 3 CCH 2 -OH + PBr 3  CH 3 CCH 2 -Br CH 3 CH 3 neopentyl alcohol 2,2-dimethyl-1-bromopropane

21. 3.Dehydration (later)

22. 4)As acids. a)With active metals: ROH + Na  RONa + ½ H 2  b)With bases: ROH + NaOH  NR! CH 4 < NH 3 < ROH < H 2 O < HF

23. CH 3 CH 2 OH + NaOH  H 2 O + CH 3 CH 2 ONa WA WB SA SB CH 3 CH 2 OH + CH 3 MgBr  CH 4 + MgBr(OCH 2 CH 3 ) SA SB WA WB CH 3 OH + NaNH 2  NH 3 + CH 3 ONa SA SB WA WB

24. 5.Ester formation. CH 3 CH 2 -OH + CH 3 CO 2 H, H +  CH 3 CO 2 CH 2 CH 3 + H 2 O CH 3 CH 2 -OH + CH 3 COCl  CH 3 CO 2 CH 2 CH 3 + HCl CH 3 -OH + CH 3 SO 2 Cl  CH 3 SO 3 CH 3 + HCl Esters are alkyl “salts” of acids.

29. oxidation states of carbon - oxidation  CH 4 CH 3 OH CH 2 O HCO 2 H CO 2 -4 -2 0 +2 +4  reduction -

30. 6.Oxidation Oxidizing agents: KMnO 4, K 2 Cr 2 O 7, CrO 3, NaOCl, etc. Primary alcohols: CH 3 CH 2 CH 2 -OH + KMnO 4, etc.  CH 3 CH 2 CO 2 H carboxylic acid Secondary alcohols: OH O CH 3 CH 2 CHCH 3 + K 2 Cr 2 O 7, etc.  CH 3 CH 2 CCH 3 ketone Teriary alcohols: no reaction.

31. Primary alcohols can also be oxidized to aldehydes: CH 3 CH 2 CH 2 -OH + C 5 H 5 NHCrO 3 Cl  CH 3 CH 2 CHO pyridinium chlorochromate aldehyde or CH 3 CH 2 CH 2 -OH + K 2 Cr 2 O 7, special conditions 

32. Alcohols, synthesis: 1. 2. 3. 4. Hydrolysis of alkyl halides (CH 3 or 1 o ) 5. 6. 7. 8.

33. Alcohols, reactions: R-|-OH 1.With HX 2.With PX 3 3.(later) RO-|-H 4.As acids 5.Ester formation 6.Oxidation