Topic 3 Synthesis, Addition, and Addition- Elimination Reactions of - - PowerPoint PPT Presentation
Chem 2312 Solomons and Fryhle: Chapters 12.1, .2 .3, Lecture 15, September 26, 2003 16.1, .2, .3, .4 Topic 3 Synthesis, Addition, and Addition- Elimination Reactions of Aldehydes and Ketones New Molecule of the Week Part - 1 H 3 C H O ( R
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Solomons and Fryhle: Chapters 12.1, .2 .3, 16.1, .2, .3, .4 Chem 2312 Lecture 15, September 26, 2003 New Molecule of the Week
Pungent, peculiar to burnt cocoa and coffee like
O H3C H
(R)-2-methylbutanal
O
Fragrance reminiscent of citronellal
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N.R.
3
N.R.
O O
O H
R R' O
Carbonyl Group
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N.R.
O
Butan-2-one Methyl,ethyl ketone
O
Cyclohexyl-cyclopentyl-methanone O
4-Methyl-hex-1-en-3-one
O
3-Methyl-pentanal
O Cl
3-Chloro-4-ethyl-benzaldehyde
O
Butan-2-one Methyl,ethyl ketone
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Methanal; common name>> formaldehyde Ethanal; common name>> acetaldehyde
O
heptanal
O
5-ethyl-7-methylnonanal
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Benzenecarbaldehyde; common name> benzaldehyde
O
cyclohexanecarbaldehyde
O O
3-methylcyclopentanecarbaldehyde cyclopropanecarbaldehyde
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Or you can also name the compound by the two R and R’ groups followed by the word ketone. >>> or dimethyl ketone.
Propanone; Common Name>>> Acetone
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O O
heptan-3-one
O
5-ethyl-7-methylnonan-4-one 1-cyclohexyl-2,2-dimethylpropan-1-one
O O
pentan-3-one pentan-2-one
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Diphenylmethanone, common name>> benzophenone Phenylethanone, common name >>> acetophenone
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O R R' O R R'
Oxygen is sp2
O O
Carbon is sp2 120o R R' Sigma Bonding
R' R
π Bonding Two sp2 orbitals each having two electrons – Lone pairs p p orbital Third sp2 for σ-bond
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N.R.
R R' O R R' O R R' O R R' O
δ- δ- δ- δ- δ+ δ+ δ+ δ+
R R' O H O H H O H H O H
Water soluble with small R groups
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N.R. 1o alcohol Aldehyde Carboxylic Acid C =-3 C=-1 C=+1 C= +3
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N.R.
R H O R OH O
N.R.
R R O
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N.R.
O OH O
R R O
RCO2H Potassium Permanganate (+7) (+6)
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N.R. R O H NB: Oxidation stops at aldehyde!!! Milder than acidic chromate Also >> remember KMnO4 Attacks double bonds
O H HO H H
PCC
`
OH O
CrO3 Acetone
NH+ CrO3Cl-
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N.R. R-CH2-OH 1o alcohol (LAH)
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N.R.
N H
O H
O H
O H
H2O DIBAL Diisobutylaluminum Hydride Lithium tri-tert-butoxy- Aluminum hydride The severe steric hinderance of these agents reduces their reactivity
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N.R.
O O O Al O O
Li
CH3 O O CH3 H Li O Al O O H O O CH3 Li H O Al O O O O CH3 Al H O O O O Al O O O H
H2O
O H
What’s Going On?????