Swern Oxidation This reaction uses dimethyl sulfoxide (DMSO) as the oxidizing agent along with oxalyl chloride and pyridine. Primary alcohols can be oxidized to the aldehyde. Secondary alcohols can be oxidized to the corresponding ketone with this reaction as well. The by-products of this reaction can be easily separated from the products,making this a convenient reaction. Chapter 11 16
Chapter 11 16 Swern Oxidation • This reaction uses dimethyl sulfoxide (DMSO) as the oxidizing agent along with oxalyl chloride and pyridine. • Primary alcohols can be oxidized to the aldehyde. • Secondary alcohols can be oxidized to the corresponding ketone with this reaction as well. • The by-products of this reaction can be easily separated from the products, making this a convenient reaction
Example of the Swern Oxidation OH +C02 (CH:CH2)N: H3C-S-CH3 +C0 CH,Cl +2HCI DMSO (COCI)2 ketone alcohol dimethyl sulfoxide oxalyl chloride or aldehyde dimethyl sulfide Examples OH DMSO.(COCI) EiN.CH.Cl,-60 cyclopentanol cyclopentanone (90%) Copyright2010 Pearson Prentice Hall,Inc. Chapter 11 17
Chapter 11 17 Example of the Swern Oxidation
Biological Oxidation Catalyzed by alcohol dehydrogenase (ADH) 。 Oxidizing agent is nicotinamide adenine dinucleotide (NAD+). · Ethanol oxidizes to acetaldehyde,then acetic acid,which is a normal metabolite. Methanol oxidizes to formaldehyde,then formic acid,which is more toxic than methanol. Ethylene glycol oxidizes to oxalic acid,which is toxic. Treatment for poisoning is excess ethanol. Chapter 11 18
Chapter 11 18 Biological Oxidation • Catalyzed by alcohol dehydrogenase (ADH). • Oxidizing agent is nicotinamide adenine dinucleotide (NAD+ ). • Ethanol oxidizes to acetaldehyde, then acetic acid, which is a normal metabolite. • Methanol oxidizes to formaldehyde, then formic acid, which is more toxic than methanol. • Ethylene glycol oxidizes to oxalic acid, which is toxic. • Treatment for poisoning is excess ethanol