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8 Cards in this Set

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The most general rxn of aldehydes and ketones is the
nucleophilic addition rxn
What happens during a nucleophilic addition rxn of Aldehydes /ketones?
- A nucleophile, :Nu-, approaches from a angle of 45 degrees to the plane of the carbonyl group and adds to the electrophilic C=O carbon atom.

- At the same time, rehybridization of the carbonyl carbon from sp2 to sp3 occurs, an electron pair from the carbon-oxygen double bond moves toward the electronegative oxygen atom, and a tetrahedral alkoxide ion intermediate is produced
The nucleophile of Aldehydes /ketones rxn can be either.....
negatively charged (:Nu-) or neutral(:Nu)
If the nucleophile of Aldehydes /ketones rxn is neutral, the nucleophile usually carries ?
a hydrogen atom that can subsequently be eliminated
What are some negatively charged nucleophiles of Aldehydes /ketones rxns
HO- (hydroxide ion)
H- (Hyride ion)
R3C- (carbanion)
RO- (an alkoxide ion)

n=-C- (cyanide ion *3 lines)
What are some neutral nucleophiles of Aldehydes /ketones rxns
HOH (water)
ROH (an alcohol)
H3N (ammonia)
RNH2 (an amine)
Nucleophile additions to aldehydes and ketones have two general variations
- the tetrahedral intermediate is pronated by water or acid to give an alcohol

- The carbonyl oxygen atom is eliminated as HO- or H2O to give a product with a C=Nu double bond
With Aldehydes /ketones rxns, we are concerned both with the reversibility of a given reaction and with the acid or base catalysis of that rxn

Facts about Nucleophilic addition rxn and catalysis
- Some Nucleophilic addition rxn take place reversibly and some do not

- Some occur w/o catalysis, but many others require acid or base to proceed