SLIDE 1
1
2
Topic 3 Synthesis, Addition, and Addition- Elimination Reactions of - - PowerPoint PPT Presentation
Topic 3 Synthesis, Addition, and Addition- Elimination Reactions of - - PowerPoint PPT Presentation
Chem 2312 Solomons and Fryhle: Chapter Sections Lecture 19, October 6, 2003 12.8A, 12.10, 16.11, 12.9 Topic 3 Synthesis, Addition, and Addition- Elimination Reactions of Aldehydes and Ketones New Molecule of the Week Part - V 1 2 O +
SLIDE 2
SLIDE 3
3
H O
+ CH
3-M
gX
CH3 O
+ LiAlH4
- r NaBH4
SLIDE 4
4
HOW?????
O- O CH3 CH3 CH3 O
CH3-MgI
CH3 OHCH3 CH3 O
+ CH3-MgX
H3C CH3 O
+ Ph-MgX
O O
+ 2 x CH3-MgX
CH3
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5
HOW????? R-CH2-OH 1o R' H OH R R-CH2-CH2-OH 1o 2o ‘
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6
HOW?????
R' R" OH R
R' R OH R
R' R N
H2O
R' R O
C N R
+ R-MgX
<< Three different R groups << Two same R groups
- - negative charge makes this species not electrophilic
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7
Note>>>>> others disconnects would not yield 4 carbon units
Mg-X O
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8
HOW?????
OH O
+
Mg-X Li
- r
Br
Mg or Li
OH
- 1. Ts-Cl
- 2. KBr
S O O Cl
LAH Or NaBH4
SLIDE 9
9
Problems>>>> How would you prepare
OH OH O O
2 x CH3MgX 1. From
HOW?????
2.. From
Br
Want>>>
Mg-Br O
+
OH
+ RCO3H
O
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10
HOW?????
OH OH
Ph-MgX excess
Ph-MgX excess INSTEAD
O O O OH
H+
O O O O
1.
- 1. H2O/H+
O O-MgX O O OH
NO No No!!!!
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HO O R3 R4 R2 R1 O
R1 O Zn R2 O Br NOTE: R-Zn-Halide is not reactive enough to react with esters>>
- nly keto and aldehyde groups
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12
Elimination!!!!!!! R X Can be viewed as a source of CH3:-
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13
Bu
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14
O
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15
HOW?????
..
O Cl O
+
CuLi
2 CuI
Li Br
Li
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Prepare From>>>>
O O
First Way
O
LAH
OH
- 1. TsCl
- 2. KBr
Br
Mg
Mg Br O OH O
PCC Second Way
O Br O O Zn O O Br O O OH
H+
O O
H2/Pt
O O
DIBAL
O
Zn
SLIDE 17
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