Alcohol Reactions

Conversions to esters (Acetate Lab) Reactions with hydrogen halides Acid-catalyzed hydrations

Esterification

condensation Fischer esterification acid catalyzed reversible Esterification ROH H2OH2OH2OH2O + H+H+H+H+ + R'COHO R'COR O

Example of Fischer Esterification H2OH2OH2OH2O + CH 3 OH + COHO COCH 3 O H 2 SO mol 0.6 mol 70% yield based on benzoic acid

High yields Not reversible when carried out in presence of pyridine. Reaction of Alcohols with Acyl Chlorides ROH HCl ++ R'CClO R'COR O

pyridine + CCl O2NO2NO2NO2NO CH 3 CH 2 CH 3 OHOHOHOH (63%) NO 2 CH 3 CH 2 CH 3 OCOCOCOC O Example

analogous to acyl chlorides Reaction of Alcohols with Acid Anhydrides ROH ++ R'COR O O R'COCR'O R'COHO

pyridine (83%) + C 6 H 5 CH 2 CH 2 OH O F 3 CCOCCF 3 O C 6 H 5 CH 2 CH 2 OCCF 3 OExample

Reactions of Alcohols “Poor”

Oxidation Conversion to ethers

Oxidation of Alcohols

Primary alcohols from H 2 O Oxidation of Alcohols RCH 2 OH ORCHORCOH Secondary alcohols O RCR'RCHR' OH

In aqueous solution: Mn(VII) Cr(VI) KMnO 4 CrO 3 / H 2 SO 4 = H 2 CrO 4 KMnO 4 CrO 3 / H 2 SO 4 = H 2 CrO 4 K 2 Cr 2 O 7 / H 2 SO 4 = H 2 Cr 2 O 7 K 2 Cr 2 O 7 / H 2 SO 4 = H 2 Cr 2 O 7 Strong Oxidizing Agents Oxidize 1 o alcohols to carboxylic acids. Cannot stop at aldehydes.

Aqueous Cr(VI) FCH 2 CH 2 CH 2 CH 2 OH K 2 Cr 2 O 7 H 2 SO 4 H2OH2OH2OH2O FCH 2 CH 2 CH 2 COH (74%)O Na 2 Cr 2 O 7 H 2 SO 4 H2OH2OH2OH2O (85%) H OH O

Question Treatment of 1-propanol with K 2 Cr 2 O 7, H 2 SO 4, and heat will produce: A)B) C)D)

What is the product of the following reaction? Question

Used in CH 2 Cl 2 Pyridinium dichromate (PDC) (C 5 H 5 NH + ) 2 Cr 2 O 7 2– Pyridinium chlorochromate (PCC) C 5 H 5 NH + ClCrO 3 – “Collins Reagent” Specialized Oxidizing Agents [ Nonaqueous Sources of Cr(VI)] Jones Reagent: CrO 3 / H 2 SO 4 acetone (does not affect Carbon=Carbon double bonds; oxidizes 2 o alcohols to ketones)

Example: Oxidation of a Primary Alcohol with PCC CH 3 (CH 2 ) 5 CH 2 OH PCC CH 2 Cl 2 O CH 3 (CH 2 ) 5 CH (78%) ClCrO 3 – N H +

Question What is the product of the reaction of 1- butanol with PCC in CH 2 Cl 2 ? A)B) C)D)

What is the product of the following reaction? What is the product of the following reaction? Question

PDC CH 2 Cl 2 O(94%) CH 2 OH (CH 3 ) 3 C CH Example: Oxidation of a Primary Alcohol with PDC

Question For the following reaction, select the statement that best describes it. (C 5 H 5 NH + ) 2 Cr 2 O 7 2– RCH 2 OH + PDC [(C 5 H 5 NH + ) 2 Cr 2 O 7 2– ]  A)The alcohol is oxidized to an acid, and the Cr(VI) is reduced. B)The alcohol is oxidized to an aldehyde, and the Cr(VI) is reduced. C)The alcohol is reduced to an aldehyde, and the Cr(III) is oxidized. D)The alcohol is oxidized to a ketone, and the Cr(VI) is reduced.

Conversion of Alcohols to Ethers

RCH 2 O H CH 2 R OH H+H+H+H+ RCH 2 O CH 2 R HOH+ Conversion of Alcohols to Ethers Acid-catalyzed Referred to as a "condensation" Equilibrium; most favorable for primary alcohols

Example 2CH 3 CH 2 CH 2 CH 2 OH H 2 SO 4, 130°C CH 3 CH 2 CH 2 CH 2 OCH 2 CH 2 CH 2 CH 3 (60%)

Intramolecular Analogue HOCH 2 CH 2 CH 2 CH 2 CH 2 OH H 2 SO 4 130° O (76%)via:O H + O H H Reaction normally works well only for 5- and 6-membered rings.

Question When 1-propanol is treated with Na 2 Cr 2 O 7 /H 2 SO 4 followed by treatment with CH 3 OH, H 2 SO 4 the product isolated is: A)propanal B)propanoic acid C)propanolD)methyl propanoate

Question I.Oxidation II.Reduction III.Neither oxidation or reduction A.I: a, c, d; II: e, f; III: b B.I: a, d, e; II: c, f; III: b C.I: c, d, e; II: a, f; III: b D.I: c, f; II: a, d, e; III: b E. I: c, e;II: a, d, f; III: b E.I: c, e;II: a, d, f; III: b Classify the following as oxidation, reduction or neither oxidation or reduction