Question

Какие химические свойства глюкозы подтверждают наличие в ней альдегидных групп?(Написать уравнения соответствующих реакций)

Answer 1

доказательство того, что глюкоза содержит альдегидрую группу являютс качественные реакции  на альдегиды (окисление):

1) реакция медного зеркала на альдегидную группу. при 

этом образуется красный осадок меди  Cu2O.

 

 

             O                                                           O

            //                                                            //

        C  –  H                                                    C - OH

         |                                                               |

H -   C – OH                                           H -   C – OH                                                 

          |                                        t                     |

HO –C – H    + 2Cu(OH)2  ------- >  HO - C – OH        + Cu2O + H2O                                          

          |                                                              |

H  -   C  – OH                                         H -   C – OH                                                                     

          |                                                              |

 H  -  C – OH                                          H -   C – OH                                                 

          |                                                              |

         CH2–OH                                                CH2–OH

2) реакция серебрянного зеркала: 

с образованием металлического серебра на стенках пробирки

             O                                                           O

            //                                                            //

        C  –  H                                                    C - OH

         |                                                               |

H -   C – OH                                           H -   C – OH                                                 

          |                                        t                     |

HO –C – H        + Ag2O       ------- >  HO - C – OH        + 2Ag                                        

          |                                                              |

H  -   C  – OH                                         H -   C – OH                                                                     

          |                                                              |

 H  -  C – OH                                          H -   C – OH                                                 

          |                                                              |

         CH2–OH                                                CH2–OH

 

 

 

 

 

 

 

 

 

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