ORGANIC CHEMISTRY Chapter 16 16.6 Nucleophilic Addition to the Carbon-Oxygen Double Bond Department of Chemistry, Xiamen University
ORGANIC CHEMISTRY Department of Chemistry, Xiamen University Chapter 16 16.6 Nucleophilic Addition to the Carbon-Oxygen Double Bond
ORGANIC CHEMISTRY Chapter 16 o The most characteristic reaction of aldehydes and ketones is nucleopl chili addition to the carbon-oxygen d d ouble bone C=0+H-Nu° C-OH Nu C=0 Nu Nucleophilic addition to the carbon-oxygen double bond occurs in either of two general ways Department of Chemistry, Xiamen University
ORGANIC CHEMISTRY Department of Chemistry, Xiamen University Chapter 16 The most characteristic reaction of aldehydes and ketones is nucleophilic addition to the carbon-oxygen double bond. C O + C OH Nu H Nu C O Nu Nucleophilic addition to the carbon-oxygen double bond occurs in either of two general ways
ORGANIC CHEMISTRY Chapter 16 Mechanisms 1. Addition of a Strong Nucleophile to an Aldehyde or Ketone R/88 R C=0 R C-O、H<M,R R LRIC-OH Nu NI NI The important aspect of this step is the ability of the carbonyl oxygen atom to accommodate the electron pair of the carbon-oXygen double bond Department of Chemistry, Xiamen University
ORGANIC CHEMISTRY Department of Chemistry, Xiamen University Chapter 16 Mechanisms Mechanisms 1. Addition of a Strong Nucleophile to an Aldehyde or Ketone C O R' R δ− δ+ Nu C O R' R Nu H Nu C OH R' R Nu The important aspect of this step is the ability of the carbonyl oxygen atom to accommodate the electron pair of the carbon-oxygen double bond
ORGANIC CHEMISTRY Chapter 16 Mechanisms 2. Acid-Catalyzed Nucleophilic Addition to an Aldehyde or Ketone H+ + e Nu-H C=0 C=OH C-OH Slow -C-OHH* -C-OH NuTH Nu Department of Chemistry, Xiamen University
ORGANIC CHEMISTRY Department of Chemistry, Xiamen University Chapter 16 Mechanisms Mechanisms 2. Acid-Catalyzed Nucleophilic Addition to an Aldehyde or Ketone C O C OH C OH C OH Nu Nu H Slow H C OH Nu H+ H+
ORGANIC CHEMISTRY Chapter 16 16.6a Reversibility of Nucleophilic Addition to the Carbon-Oxygen Double Bond Many nucleophilic additions to carbon-oxygen double bonds are reversible o The overall results of these reactions depend on the position of an equilibrium R R OH C=0 NaHSO2= H H SO3 Na (CH3) (CH3) Department of Chemistry, Xiamen University
ORGANIC CHEMISTRY Department of Chemistry, Xiamen University Chapter 16 16.6A Reversibility of Nucleophilic Addition to the Carbon-Oxygen Double Bond Many nucleophilic additions to carbon-oxygen double bonds are reversible, The overall results of these reactions depend on the position of an equilibrium. R C H O (CH3) + NaHSO3 R C H SO3Na OH (CH3)