14-羧酸衍生物

酯::水解

  • 酯的水解：酯化反应的逆反应
  • 影响因素：升温、加酸碱催化剂可加快反应

酯的碱性水解（皂化）制羧酸和醇

\(\ce{-\overset{\underset{||}{O}}{C}-O- <=>[OH-][慢] -\overset{\underset{\!\!\phantom{⤸}|⤸\!\!}{\!\!\phantom{^-}O^-\!\!}}{\underset{\overset{|}{\!\!\!\!\phantom{H}OH\!\!\!\!}}{C}}\overset{_↷\!\!\!\!}{\phantom{}-\phantom{}}O- <=>[快] -\overset{\underset{||}{O}}{\underset{\overset{|}{\!\!\!\!\phantom{H}OH\!\!\!\!}}{C}}\ \ + ^-O-\phantom{} ->[快] -\overset{\underset{||}{O}}{\underset{\overset{|}{\!\!\phantom{^-}O^-\!\!}}{C}}\ \ + HO-\phantom{}}\)

  • 碱性水解双分子酰氧断裂机理 \(\text{B}_\text{AC}2\)

酯的酸性水解（酸催化）制羧酸和醇

\(\ce{-\overset{\underset{||}{O}}{C}-O- + H2O <=>[H+] -\overset{\underset{|}{\!\!\!\!\phantom{H}OH\!\!\!\!}}{\underset{\overset{|}{\!\!\!\!\!\!\phantom{H}^+OH2\!\!\!\!\!\!}}{C}}-O- <=> -\overset{\underset{|}{\!\!\!\!\phantom{H}OH\!\!\!\!}}{\underset{\overset{|}{\!\!\!\!\phantom{H}OH\!\!\!\!}}{C}}-\underset{\overset{|}{H}}{\overset{_+}{O}}- <=> -\overset{\underset{||}{\!\!\!\!\phantom{H}\overset{+}{O}H\!\!\!\!}}{\underset{\overset{|}{\!\!\!\!\phantom{H}OH\!\!\!\!}}{C}}\ \ + HO-\phantom{}}\)

  • 酸性水解双分子酰氧断裂机理 \(\text{A}_\text{AC}2\)

酰氯、酸酐、酯、酰胺::亲核取代

  • 机理（亲核取代，先加成后消除）：\(\substack{\ce{R-C}}\left.\small\substack{\!\!\diagup\!\!\diagup\!\!\\\diagdown}\right.\!\substack{‥\\\!\phantom{⁚}\ce{O}⁚\!\\\phantom{|}\\\ce{L}\\\phantom{|}}\ce{ + \substack{\ce{⁚Nu-}} <=> }\substack{\phantom{_-\ }‥\ _-\\\ce{⁚O⁚}\\_{\phantom{↷\ ⤸\ }|\ ⤸\ ↷}\\\ce{R-C-L}\\_|\\\ce{Nu}\!\!\\\phantom{|}}\ce{ -> }\substack{\ce{R-C}}\left.\small\substack{\!\!\diagup\!\!\diagup\!\!\\\diagdown}\right.\!\substack{‥\\\!\phantom{⁚}\ce{O}⁚\!\\\phantom{|}\\\ce{Nu\!\!}\\\phantom{|}}\ce{ + \substack{\ce{⁚L-}} }\)
  • 亲核反应活性（酰氯、酸酐常作酰基化剂）：酰卤 > 酸酐 > 醛 > 酮 > 羧酸 ~ 酯 > 酰胺

水解成羧、醇解成酯

\(\cdots\) \(\ce{->[H2O][条件]}\) 水解成羧 \(\ce{->[R-OH]}\) 醇解成酯
\(\ce{-\overset{\underset{\vert\vert}{O}}{C}-Cl}\) \(\ce{->[H2O]\ -\overset{\underset{\vert\vert}{O}}{C}-OH\ +\ HCl}\) \(\ce{-\overset{\underset{\vert\vert}{O}}{C}-OR\ +\ HCl}\)
\(\ce{-\overset{\underset{\vert\vert}{O}}{C}-O-\overset{\underset{\vert\vert}{O}}{C}-}\) \(\ce{->[H2O][\Delta]\ -\overset{\underset{\vert\vert}{O}}{C}-OH\ +\ HO-\overset{\underset{\vert\vert}{O}}{C}-}\) \(\ce{-\overset{\underset{\vert\vert}{O}}{C}-OR\ +\ HO-\overset{\underset{\vert\vert}{O}}{C}-}\)
\(\ce{-\overset{\underset{\vert\vert}{O}}{C}-O-}\) \(\ce{->[H2O,\ H+\ 或\ OH-][\Delta]\ -\overset{\underset{\vert\vert}{O}}{C}-OH\ +\ HO-\phantom{}}\) \(\ce{-\overset{\underset{\vert\vert}{O}}{C}-OR\ +\ HO-\phantom{}}\)
\(\ce{-\overset{\underset{\vert\vert}{O}}{C}-NH2}\) \(\ce{->[H2O,\ H+\ 或\ OH-][长时间回流]\ -\overset{\underset{\vert\vert}{O}}{C}-OH\ +\ NH3\uparrow}\) \(\ce{-\overset{\underset{\vert\vert}{O}}{C}-OR\ +\ NH3\uparrow}\)
  1. \(\ce{->[H2O][条件]}\) 水解成羧
    • 酰氯 > 酸酐 > 酯 > 酰胺（反应活性）
  2. \(\ce{->[R-OH]}\) 醇解成酯
    • 酰氯醇解制酯、酰胺（常用 \(\ce{OH-}\) 吸 \(\ce{HCl}\)，可用无机碱，也可用 \(\ce{N,N-\phantom{}}\)二甲基苯胺、吡啶、三乙胺等有机碱）
    • 酯、酰胺醇解反应可逆
  3. \(\ce{->[R-OH,\ C6H6,\ 对甲苯磺酸][回流,\ 分水]}\) 环酐醇解成单酯
    • \(⌬\left.\small\substack{\diagup\\\phantom{+}\\\diagdown}\right.\!\substack{\ce{C}\\\phantom{|}\\\ce{C}}\!\!\left.\small\substack{\diagup\!\!\diagup\\\phantom{.}\\\diagdown\\\phantom{.}\\\diagup\\\phantom{.}\\\diagdown\!\!\diagdown}\right.\!\!\substack{\ce{O}\\\phantom{.}\\\phantom{|}\\\ce{O}\\\phantom{.}\\\phantom{|}\\\ce{O}}\ce{\ ->[R-OH,\ C6H6,\ 对甲苯磺酸][回流,\ 分水]\ }⌬_\ce{-COOR}^\ce{-COOR}\)

酸解成羧（或酯）、胺解成酰胺

\(\cdots\) \(\ce{<=>[R-COOH][+吡啶]}\) 酸解成羧（或酯） \(\ce{->[NH3]}\) 胺解成酰胺
\(\ce{-\overset{\underset{\vert\vert}{O}}{C}-Cl}\) \(\ce{-\overset{\underset{\vert\vert}{O}}{C}-OH\ +\ R-\overset{\underset{\vert\vert}{O}}{C}-Cl}\)（或 \(\ce{-\overset{\underset{\vert\vert}{O}}{C}-O-\overset{\underset{\vert\vert}{O}}{C}-R + C5H5N.HCl}\)） \(\ce{-\overset{\underset{\vert\vert}{O}}{C}-NH2\ +\ NH4Cl}\)
\(\ce{-\overset{\underset{\vert\vert}{O}}{C}-O-\overset{\underset{\vert\vert}{O}}{C}-}\) \(\ce{-\overset{\underset{\vert\vert}{O}}{C}-OH\ +\ R-\overset{\underset{\vert\vert}{O}}{C}-O-\overset{\underset{\vert\vert}{O}}{C}-}\) \(\ce{-\overset{\underset{\vert\vert}{O}}{C}-NH2\ +\ NH4-O-\overset{\underset{\vert\vert}{O}}{C}-}\)
\(\ce{-\overset{\underset{\vert\vert}{O}}{C}-O-}\) \(\ce{-\overset{\underset{\vert\vert}{O}}{C}-OH\ +\ R-\overset{\underset{\vert\vert}{O}}{C}-O-\phantom{}}\) \(\ce{-\overset{\underset{\vert\vert}{O}}{C}-NH2\ +\ HO-\phantom{}}\)
\(\ce{-\overset{\underset{\vert\vert}{O}}{C}-NH2}\) \(\ce{-\overset{\underset{\vert\vert}{O}}{C}-OH\ +\ R-\overset{\underset{\vert\vert}{O}}{C}-NH2}\) \(\ce{->[R'NH2][过量]\ -\overset{\underset{\vert\vert}{O}}{C}-NHR\ +\ NH3\uparrow}\)
  1. \(\ce{<=>[R-COOH][+吡啶]}\) 酸解成羧（或酯）
  2. \(\ce{->[NH3]}\) 胺解成酰胺
    • \(\ce{-NH2 ->[(CH3CO)2O] -NHCOCH3 ->[KOH][EtOH,\ \Delta] -NH2}\)（酰氯、酸酐氨解保护氨基）
    • \(⌬\left.\small\substack{\diagup\\\phantom{+}\\\diagdown}\right.\!\substack{\ce{C}\\\phantom{|}\\\ce{C}}\!\!\left.\small\substack{\diagup\!\!\diagup\\\phantom{.}\\\diagdown\\\phantom{.}\\\diagup\\\phantom{.}\\\diagdown\!\!\diagdown}\right.\!\!\substack{\ce{O}\\\phantom{.}\\\phantom{|}\\\ce{O}\\\phantom{.}\\\phantom{|}\\\ce{O}}\ce{ ->[\substack{\ce{H}\\\phantom{|}\\\ce{H}}\substack{\diagdown\\\diagup}\substack{\ce{NCH3}}] }⌬\left.\small\substack{\diagup\\\phantom{+}\\\diagdown}\right.\!\substack{\ce{C}\\\phantom{|}\\\ce{C}}\!\!\left.\small\substack{\diagup\!\!\diagup\\\phantom{.}\\\diagdown\\\phantom{.}\\\diagup\\\phantom{.}\\\diagdown\!\!\diagdown}\right.\!\!\substack{\ce{O}\\\phantom{+}\\\ce{\!\!\!\!\!\!\!\!\!\!\!\!\phantom{HCH3}NHCH3\!\!\!\!\!\!\!\!\!\!\!\!}\\\ce{\!\!\!\!\phantom{H}OH\!\!\!\!}\\\phantom{+}\\\ce{O}}\qquad\ce{ ->[\Delta] }⌬\left.\small\substack{\diagup\\\phantom{+}\\\diagdown}\right.\!\substack{\ce{C}\\\phantom{|}\\\ce{C}}\!\!\left.\small\substack{\diagup\!\!\diagup\\\phantom{.}\\\diagdown\\\phantom{.}\\\diagup\\\phantom{.}\\\diagdown\!\!\diagdown}\right.\!\!\substack{\ce{O}\\\phantom{.}\\\phantom{|}\\\ce{\phantom{N}}\\\phantom{.}\\\phantom{|}\\\ce{O}}\!\!\!\!\!\substack{\ce{\phantom{^3}NCH3}}\)（环酐易制环状酰亚胺）
    • 酯可 \(\ce{->[NH3]}\) 氨解或胺解，氨或胺置换酯中烷氧基制酰胺
    • 酰胺可 \(\ce{->[R'NH2][过量]}\) 得 N-烷基酰胺，但反应可逆，作用不大

酰氯、酯、酰胺::还原

酰氯还原制醇

\(\ce{-\overset{\underset{\vert\vert}{O}}{C}-Cl ->[H2,\ Pd][(或\ LiAlH4,\ HCl)]\ -CH2OH}\)

酰氯还原制羧

\(\ce{-\overset{\underset{\vert\vert}{O}}{C}-Cl->[H2,\ Pd,\ BaSO4]\ -\overset{\underset{\vert\vert}{O}}{C}-OH}\)

酯还原制乙醇

\(\ce{-\overset{\underset{\vert\vert}{O}}{C}-O- ->[Na,\ C2H5OH,\ \Delta][(或\ LiAlH4,\ H2O)] -CH2OH + HO-\phantom{}}\)

酰胺还原制伯胺

\(\ce{-\overset{\underset{\vert\vert}{O}}{C}-\overset{|}{N}- ->[LiAlH4] -CH2-\overset{|}{N}-}\)

腈、烯酮::性质

酰胺脱水制腈

\(\ce{-\overset{\underset{||}{O}}{C}-NH2 ->[P2O5] -C#N}\)

  • 常用脱水剂：\(\ce{P2O5}\)，\(\ce{POCl3}\)，\(\ce{PCl5}\)，\(\ce{SOCl2}\) 等

羧酸铵盐脱水制腈

\(\ce{-\overset{\underset{||}{O}}{C}-O^-NH3^+ ->[脱水剂][\Delta] -C#N + 2H2O}\)

posted @ 2024-11-14 00:09  湘秋  阅读(57)  评论(0)    收藏  举报