3. By oxidation of alkylbenzenes 1)KMnO4, OH CH HCOOH 2)H3O 1)KMnO4, Oh COOH 2)H3O COOH 4. By oxidation of methyl ketones (甲基酮的氧化) )X2/ NaOH c—CH C6H5COOH CHX3 2)H3O (卤仿反应) )X2/NaOH R—c—cH H RCOOH CHX3 2)H3O (卤仿反应)
3. By oxidation of alkylbenzenes. 2) H3O + 1) KMnO4 , OH - 2) H3O + CH3 C6H5COOH COOH COOH 1) KMnO4 , OH- 4. By oxidation of methyl ketones. （甲基酮的氧化） 2) H3O + C C6H5COOH 1) X2 / NaOH O CH3 + CHX3 (卤 仿 反 应 ） R C O CH3 2) H3O + RCOOH 1) X2 / NaOH + CHX3 (卤 仿 反 应 ）
5. By hydrolysis of cyanohydrins and other nitriles(腈醇和腈的水解) R R OH R OH H+ -o + HCN 3 R HbO R CN COOH RCH,X t Nacn RCH, COOH H2O H3O BrCH2CH2CH2CH2Br- Nacn NC(ch,)cn- HooC(CH,).COoH 在合成上增加一个碳原子的羧酸
5. By hydrolysis of cyanohydrins and other nitriles.(腈醇和腈的水解） R R' O + HCN R C R' OH CN H + H2O R C R' OH COOH RCH2X + NaCN RCH2COOH H + H2O BrCH2CH2CH2CH2Br NaCN NC(CH2 ) 4CN H3O + HOOC(CH2 ) 4COOH 在合成上增加一个碳原子的羧酸
6. By carbonation(羰基化)of Grignard reagents Grigard reagents react with carbon dioxide to yield magnesium carbon dioxide to yield magnesium carboxylates Acidification produces carboxylic acids. 0=C=0 R——X RMgX R—c=0 diethyl ether Grignard reagents OMg H3O R—c=0 X o=C=0 Br t M PhLox Ph-C=0 diethyl ether Grignard reagents OMx HO Ph-C=O OH Mg X OH
6. By carbonation（羰基化） of Grignard reagents. Grigard reagents react with carbon dioxide to yield magnesium carbon dioxide to yield magnesium carboxylates. Acidification produces carboxylic acids. R X + Mg diethyl ether RMgX O C O R C O OMgX H3O + R C O OH + Mg OH X Br + Mg diethyl ether PhMgX O C O Ph C O OMgX H3O + Ph C O OH + Mg OH X Grignard reagents Grignard reagents