How is your laboratory research project going? Please write up
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To get ready for exam # 1, prepare a one-page (8 x 11, front and back)
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Finish Chapter 17
I. Nucleophilic addition to alpha-beta-unsaturated aldehydes and
ketones
A. Direct addition (added to the carbonyl
group) favored when a strong nucleophile (base) is used and the reaction
is irreversible.
B. Conjugated addition (addition across the
conjugated system) favored when a weak nucleophiles (bases) are used.
II. Nucleophilic Addition to alpha-beta-unsaturated carboxylic
acid derivatives.
A. Conjugated addition with weak nucleophiles
(bases)
B. Strong nucleophiles for nucleophilic acyl
substitution products.
Chapter 18 More About Oxidation-Reduction Reactions
I. Oxidation States of Carbon
II. Reduction Reactions
A. Reduction by two hydrogen atoms (catalytic
hydrogenations).
1. Alkenes, alkynes,
imines, and nitriles are reduced by H2 and Pt, Pd, or Ni
2. Alkynes to cis-alkenes
with a H2 and a Lindlar's catalyst
3. Carbonyl group
of aldehydes and ketones with H2 and Rainey Ni
4. Acyl chloride reduced
to alcohol, stopped at aldehyde with partially deactivated Pd.
5. Carboxylic acids,
esters, and amides not reduced by catalytic hydrogenation.
6. Increasing reactivity
toward H2, Pd/C: imine < nitrile < ketone < alkene <
aldehyde < alkyne < acyl chloride
B. Reduction by addition of an electron, a
proton, an electron, a proton
1. Dissolving metal
reduction: Alkyne is reduced to a trans alkene by sodium in liquid
ammonia. Sodium donates an electron and ammonia donates a proton.
C. Reduction by a hydride ion and a proton
1. Aldehydes and ketones
are reduced by NaBH4 and LiAlH4
2. Carboxylic acids,
esters, and amides are reduced by LiAlH4
a. amides are reduced to amines
3. Sterically bulky
hydrides reduce esters and acyl chlorides to aldehydes.
4. Alkenes and Alkynes
are not reduced by hydride ions.
5. increasing reactivity
toward H-, hydride ion: nitrile < amide < caboxylic acid <
ester < imine < ketone < aldehyde < acyl chloride
III. Oxidation of Alcohols
A. H2CrO4 (CrO3 or Na2Cr2O7 in aqueous acid)
most commonly used to oxidize 1o alcohol to carboxylic acid and 2o alcohol
to ketone.
B. Pyridinium chlorochromate (PCC) is used
to oxidize a 1o alcohol to an aldehyde.
C. Swern oxidation: no toxic chromium,
dimethyl sulfoxide, stops at aldehyde
D. 3o alcohols not oxidized
IV. Oxidation of Aldehydes and Ketones
A. Aldehydes are easily oxidized to carboxylic
acids using any reagent that oxidizes a 1o alcohol to a carboxylic acid..
1. Tollen's Reagent:
Ag2O, NH3, mild reagent oxidizes aldehyde to carboxylic acid, but not 1o
alcohol. Silver mirror test.
2. Baeyer-Villiger
oxidation: peroxyacid, oxidizes an aldehyde to a carboxylic acid
and a ketone to an ester.
V. Oxidation of Alkenes with Peroxyacids.
A. An epoxide is formed.
1. concerted reaction
2. more substituted
alkenes react faster
3. stereospecific
VI. Hydroxylation of Alkenes
A. Alkenes are oxidizes to 1,2-diols (vicinal
diols) by KMnO4 or OsO4
VII. Oxidative Cleavage of 1,2-diols with HIO4.
VIII. Oxidative Cleavage of Alkenes.
A. Use O3 and a "work-up"
B. KMnO4 with acid or base and heat
IX. Oxidative Cleavage of Alkynes use O3 no work-up needed
X. Designing a Synthesis V: Functional Group Interconversion
Chapter 19 Carbonyl Compounds III, Reactions at the alpha-carbon
I. Acidity of the alpha-carbon p. 828
II. Keto-Enol Tautomerism
III. Reactivity Consideration