-
- - The mechanism has two steps.
- - H:– adds to the planar C=O from
- both sides.
-
- - The mechanism has two steps.
- - R:– adds to the planar C=O from
- both sides.
-
- - The mechanism has two steps.
- - –CN adds to the planar C=O from both
- sides.
-
- - The reaction forms a new C–C σ bond and a
- new C–C π bond.
- • Ph3P=O is formed as by-product.
-
- - The reaction is fastest at pH 4–5.
- - The intermediate carbinolamine is unstable, and loses H2O to form the C=N.
-
- - The reaction is fastest at pH 4–5.
- • The intermediate carbinolamine is unstable, and loses H2O to form the C=C.
-
- - The reaction is reversible. Equilibrium favors
- the product only with less stable carbonyl
- compounds (e.g., H2CO and Cl3CCHO).
- • The reaction is catalyzed with either H+ or –OH.
-
- - The reaction is reversible.
- - The reaction is catalyzed with acid.
- - Removal of H2O drives the equilibrium
- to favor the products.
-
- - Step [1] is best with CH3X and RCH2X since the reaction follows an SN2 mechanism.
- - A strong base is needed for proton removal in Step [2].
-
- This reaction is the reverse of cyanohydrin
- formation.
-
-
-
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