Definition of Ethers, Slides of Organic Chemistry

Download Definition of Ethers and more Slides Organic Chemistry in PDF only on Docsity! Ethers R-O-R or R-O-R´ Nomenclature: simple ethers are named: “alkyl alkyl ether” “dialkyl ether” if symmetric CH3 CH3 CH3CH2-O-CH2CH3 CH3CH-O-CHCH3 diethyl ether diisopropyl ether CH3-O-C(CH3)3 tert-butyl methyl ether (MTBE) If complex, the ether part is named as an “alkoxy” group: CH3-O- = methoxy CH3CH2-O- = ethoxy, etc. CH3-O-CH2CH2CH2-O-CH3 1,3-dimethoxypropane HO-CH2CH2-O-CH2CH3 2-ethoxyethanol Synthesis of ethers 1. Williamson Synthesis. R-O-Na+ + R´-X  R-O-R´ + NaX R´-X should be CH3 or 1o SN2 mechanism Mechanism for the Williamson Synthesis = SN2 R´-X should be CH3 or 1o R O + R' X RDS R O R' + X R-OH + Na  R-O-Na+  R-O-R´ R´-OH + HX  R´-X (CH3)2CH-OH + Na  (CH3)2CH-O-Na+ +  CH3CH2CH2-O-CH(CH3)2 CH3CH2CH2-OH + HBr  CH3CH2CH2-Br isopropyl n-propyl ether note: the alkyl halide is primary!  Acids Bases Metals Oxid. Reduc. Halogens NR NR   NR   some NR NR   NR NR NR  NR NR  NR NR NR NR NR NR R-H R-X R-OH R-O-R Reactions, ethers: 1. Acid cleavage. R-O-R´ + (conc) HX, heat  R-X + R´-X CH3CH2-O-CH2CH3 + HBr, heat  2 CH3CH2-Br Mechanism 1) O CH2CH3CH3CH2 + HX H O CH2CH3CH3CH2 + X H O CH2CH3CH3CH22) X + CH3CH2 X + HO CH2CH3 3) CH3CH2 OH + HX CH3CH2 OH2 4) CH3CH2 OH2 + X CH3CH2 X + H2O + X SN2 SN2 Alcohols: nomenclature syntheses later reactions 1. HX 2. PX3 3. 4. as acids 5. ester formation 6. oxidation Ethers nomenclature syntheses 1. Williamson Synthesis 2. reactions 1. acid cleavage Mechanisms: Free radical substitution SN2 SN1 Memorize (all steps, curved arrow formalism, RDS) and know which reactions go by these mechanisms!