Acylation then Reduction = Alkylation
Chapter 12 :
Reactions of Arenes. Electrophilic Aromatic Substitution
Clemmensen Reduction (acidic
Wolff-Kishner Reduction (basic
- Zn(Hg) in HCl reduced the C=O into -CH2-
- NH2NH2 / KOH / ethylene glycol (a high boiling solvent)
reduces the C=O into -CH2-
- These reduction methods do not reduce C=C or C≡C nor -CO2H
- The combination of either one of these methods after a Friedel-Crafts acylation
gives the equivalent of alkylation but without the problems and complications
associated with carbocation rearrangements.
- The choice of method should be made based on the tolerance of other functional
groups in the system to the acidic or basic reaction conditions.