1. Alcohols, Phenols &Thiols

2. ALCOHOLS

3. Classification and Nomenclature of Alcohols
Alcohols, and Phenols 
Alcohols and phenols may be viewed as organic derivatives of water. 
Alcohols and phenols have a common functional group, the hydroxyl group, —OH. 
In alcohols the hydroxyl group is attached to an alkyl group, —R. 
In phenols the hydroxyl function is attached to an aromatic ring, Ar.
Classification and Nomenclature of Alcohols 
Alcohols are classified into:

4. IUPAC Name
1. Select the longest continuous carbon chain that contains OH group. Replace the ending the suffix -ol .
2. If a molecule contains both an -OH group and a C=C or C≡C triple bond.
The name should include both the hydroxyl and the unsaturated groups.
The -OH group takes preference before the double or triple bonds in getting the lower number.
If a compound contains both OH and a double or triple bond, choose the chain that include them both even if this is not the longest chain. -

5. 4- Cyclic alcohol, no. starts from C near to OH
3. In the IUPAC system.
The suffix diol is added to the name of the parent hydrocarbon when there are two OH groups. triol is added when there are three OH group
Two OH groups on adjacent carbons are known as 1,2-glycols.
2 OH groups on the same carbon make the compound less stable
4- Cyclic alcohol, no. starts from C near to OH

6. Secondary and tertiary alcohol
Common name
listing the alkyl substitutents attached to the hydroxyl group, followed by the word alcohol.
Primary alcohol
CH3OH CH3CH2OH CH2=CHCH2OH
Common Methyl alcohol Ethyl alcohol Allyl alcohol
IUPAC Methanol Ethanol Propen-1-ol
Secondary and tertiary alcohol

7. Chair form

9. Physical Properties of Alcohols
Solubility
As the number of carbons in the alcohol increases, the solubility in water decreases. when No. of OH  Soluble. in H2Oinc.
Triols Diols and are more soluble in water than monohydroxy alcohols.
Boiling points
The boiling points increase with increase in molecular weights.
The Increase of alcohol BP. is due to the presence of hydrogen bonding
BP. In straight chains is higher than branched

10. Alcohols are week acids.
In isomer BP. Dec. with  in alkyl gp  < 2<1
alcohol BP. Higher than it is alkanes ( hydrogen bond)
Alcohols are week acids.
Alcohol weaker acids than phenol and carboxylic acids

11. Acidity of alcohol ROH weaker as acid than H2O ALKOXIDE Hydroxide
RO-˃ OH- BASICITY
CH3OH IS THE MOST ACIDIC ALCOHOL, BECAUSE ITS COJUGATE BASE IS THE MOST STABLE δ

12. Synthesis (Preparation) of Alcohols
1. From alkene

14. 2– From alkyl halid

15. Reducing agents
In alkenes, aldehydes, and ketones will broke the = bond (C=C, C=O) and add 2H, but in carboxylic acid will also remove one (O)
Ni or Pd or Pt / H2 (very strong will also break the C=C)
NaBH4 (weak, FOR ONLY ALDEHYDE & KETONE)
LiAlH4 (strong FOR All C=O)

16. 3] From reduction of aldehyd , ketones & carboxylic acid:
Reducing agent :
NaBH4 /H2O ( for ONLY aldehyde or ketone)
H2 / Pt or Pd or Ni, (all=)
Li Al H4 /dry ether (all C=O)
for (1 , 2 only) 1
1 ROH
aldehyde 2
2 ROH
ketone
Carboxylic acid
1 ROH 2 2 2 2 1 2 2

17. 4] From Grignard reagent:
for (1 , 2 & 3)
a) with aldehyde :
ALDEHYDE GIVE 1&2 ROH
KETONE GIVE 3 ROH
ESTER GIVE 3 ROH
EPOXIDE GIVE 1&2
b) with ketones:

18. c) with ester: need 2eq. RMgX
d) with epoxide:

19. Reactions of Alcohols 1-Dehydration (Elimination Reactions) : E1 & E2
(Dissociation of R-OH Bond)
1-Dehydration (Elimination Reactions) : E1 & E2
Zaitsev’s Rule
If there are different protons can be eliminated with the hydroxyl group or with halogen atom, in this case more than one alkene can be formed, the major product will be the alkene with the most alkyl substituents attached to the double bonded carbon. And the second will be the minor product.
symmetrical 2◦ 2◦ or
Only one product

20. 2] Reaction with alkyl halides (Substitution Reaction) :

21. 3] Formation of ether

22. (Dissociation of RO-H Bond) 1- Salt Formation
Active metal: Na, K or Mg

23. Oxidizing agents
In alcohols, aldehyde will form the = bond (C=O) and remove 2H, but to oxidize the aldehyde just add (+O)
Cu/ Heat (weak)
CrO3/ Pyridine (weak)
(STRONG):KMnO4, K2Cr2O7,
H2Cr2O7, HNO3
1 ROH
RCOH
RCOOH
2 ROH
RCOR’
2 RCOOH
3 ROH
RCOR’
2 RCOOH
Lower carbon number than the used alcohol
Basicity solution
Acid solution NR
Oxidation of alcohol

24. 2] Oxidation: 1 2 3

25. 3] Esterification: alcohol + acid or their derivatives Ester
a) Inorganic ester
Alcohols reacts with HO-X inorganic acids,
X could be: NO
NO2
SO3H
H2PO3
Cl, Br, F, I

26. b) Sulphuric acid ester
c) Carboxylic acid ester

27. PHENOLS

28. Nomenclature and acidity of Phenols
Phenols are generally named as derivatives of the simplest member of the family, phenol.
Phenols is an hydroxyl group attached directly to a benzene ring e

30. (NO2) is e with. (deact.gp) acidity (CH3)is dona.gp. acidity
Acidity of Phenols
Introduction of electron-withdrawing groups, such as NO2 or CN, on the ring increases the acidity of phenols.
(NO2) is e with. (deact.gp) acidity (CH3)is dona.gp. acidity
Introduction of electron-withdrawing groups, such as NO2 or CN, on the ring increases the acidity of phenols.
Alcohols and phenols have weak acidic properties.
Phenols are much stronger acids than alcohols.

31. Preparation of phenols
1-From Diazonium salts:
2-From alkali fusion of sodium benzene-sulfonates:

32. Salt formation via strong base or active metal
Williamson ether synthesis
Ester formation
Friedel-Crafts acylation: Fries rearrangement
Halogenation
Coupling with diazonium salts
Kolbe-Schmitt Carboxylation
Reimer-Tiemann reaction
Reactions of Phenols

33. Williamson ether synthesis
Salt formation via strong base or active metal
Ester formation
Friedel-Crafts acylation: Fries rearrangement
Kolbe-Schmitt Carboxylation
Reimer-Tiemann reaction
Coupling with diazonium salts

34. 2-Reaction of aromatic nucleus of phenol (Electrophilic Substitution)
CCl4
Halogenation

35. Reimer-Tiemann Reaction Mechanism2 - -2 OH

36. THIOLS

37. Thiols and Sulfides Thiols (RSH), are sulfur analogs of alcohols
Named with the suffix -thiol
SH group is called “mercapto group” (“capturer of mercury”)

38. Thiols: Formation and Reaction
From alkyl halides by displacement with a sulfur nucleophile such as –SH
The alkylthiol product can undergo further reaction with the alkyl halide to give a symmetrical sulfide, giving a poorer yield of the thiol

39. Sulfides Sulfides (RSR), are sulfur analogs of ethers
Named by rules used for ethers, with sulfide in place of ether for simple compounds and alkylthio in place of alkoxy

40. Using Thiourea to Form Alkylthiols
Thiols can undergo further reaction with the alkyl halide to give dialkyl sulfides
For a pure alkylthiol use thiourea (NH2(C=S)NH2) as the nucleophile
This gives an intermediate alkylisothiourea salt, which is hydrolyzed cleanly to the alkyl thiourea

41. Oxidation of Thiols to Disulfides
Reaction of an alkyl thiol (RSH) with bromine or iodine gives a disulfide (RSSR)
The thiol is oxidized in the process and the halogen is reduced

42. Sulfides
Thiolates (RS) are formed by the reaction of a thiol with a base
Thiolates react with primary or secondary alkyl halide to give sulfides (RSR’)
Thiolates are excellent nucleophiles and react with many electrophiles

43. Sulfides as Nucleophiles
Sulfur compounds are more nucleophilic than their oxygen-compound analogs
3p electrons valence electrons (on S) are less tightly held than 2p electrons (on O)
Sulfides react with primary alkyl halides (SN2) to give trialkylsulfonium salts (R3S+)

44. Oxidation of Sulfides
Sulfides are easily oxidized with H2O2 to the sulfoxide (R2SO)
Oxidation of a sulfoxide with a peroxyacid yields a sulfone (R2SO2)
Dimethyl sulfoxide (DMSO) is often used as a polar aprotic solvent