methods for the synthesis of alcohols (to date) · methods for the synthesis of alcohols (to date)...
TRANSCRIPT
![Page 1: METHODS FOR THE SYNTHESIS OF ALCOHOLS (to date) · METHODS FOR THE SYNTHESIS OF ALCOHOLS (to date) Ketones Aldehydes epoxides I OH-OH 1. BH3 OH 2. NaOH/H2O2 H+/H 2O OH OH 1. OsO4](https://reader033.vdocuments.site/reader033/viewer/2022060909/60a385df4e450d21dc256e69/html5/thumbnails/1.jpg)
![Page 2: METHODS FOR THE SYNTHESIS OF ALCOHOLS (to date) · METHODS FOR THE SYNTHESIS OF ALCOHOLS (to date) Ketones Aldehydes epoxides I OH-OH 1. BH3 OH 2. NaOH/H2O2 H+/H 2O OH OH 1. OsO4](https://reader033.vdocuments.site/reader033/viewer/2022060909/60a385df4e450d21dc256e69/html5/thumbnails/2.jpg)
R
O
RNa OH
RR
R
O
H
O
R
OH
HR
OHR
METHODS FOR THE SYNTHESIS OF ALCOHOLS (to date)
Ketones
Aldehydes
epoxides
I OH-OH
1. BH3 OH2. NaOH/H2O2
H+/H2O OH
OHOH1. OsO4
2. H2O2
OH
OH
1. mCPBA
2. H+/H2OSYN ANTI
![Page 3: METHODS FOR THE SYNTHESIS OF ALCOHOLS (to date) · METHODS FOR THE SYNTHESIS OF ALCOHOLS (to date) Ketones Aldehydes epoxides I OH-OH 1. BH3 OH 2. NaOH/H2O2 H+/H 2O OH OH 1. OsO4](https://reader033.vdocuments.site/reader033/viewer/2022060909/60a385df4e450d21dc256e69/html5/thumbnails/3.jpg)
ELECTROPHILIC AND NUCLEOPHIC CARBONMethylmagnesium bromide Methyl lithium Methyl chloride
Mg BrH3Cd- d+
LiH3Cd- d+
ClH3Cd-d+
![Page 4: METHODS FOR THE SYNTHESIS OF ALCOHOLS (to date) · METHODS FOR THE SYNTHESIS OF ALCOHOLS (to date) Ketones Aldehydes epoxides I OH-OH 1. BH3 OH 2. NaOH/H2O2 H+/H 2O OH OH 1. OsO4](https://reader033.vdocuments.site/reader033/viewer/2022060909/60a385df4e450d21dc256e69/html5/thumbnails/4.jpg)
Methyl chloride
ClH3Cd-d+
O
d+
d-
acetone
TYPICAL ELECTROPHILES
![Page 5: METHODS FOR THE SYNTHESIS OF ALCOHOLS (to date) · METHODS FOR THE SYNTHESIS OF ALCOHOLS (to date) Ketones Aldehydes epoxides I OH-OH 1. BH3 OH 2. NaOH/H2O2 H+/H 2O OH OH 1. OsO4](https://reader033.vdocuments.site/reader033/viewer/2022060909/60a385df4e450d21dc256e69/html5/thumbnails/5.jpg)
Alcohols, carbonyl compounds and carboxylic acids:REDUCTION
R C
O
OH
LiAlH4R C
O
H
R C
O
R'
NaBH4
NaBH4
R C OHH
H
R C OHH
R'
R C OHR"
R'
R C HH
H
R C HH
R'
R C HR"
R'
Primary alcohol
Secondary alcohol
Tertiary alcohol
Aldehyde
Ketone
Carboxylic acid
Reduction: Addition of H2 (or H-), loss of O or O2; loss of X2
must convert OH toleaving group
or Raney Ni/
H2
or Raney Ni/
H2
must convert OH toleaving group
Li AlH
HHH Na B
H
HHH
Lithium aluminiumhydride
Sodium borohydride
![Page 6: METHODS FOR THE SYNTHESIS OF ALCOHOLS (to date) · METHODS FOR THE SYNTHESIS OF ALCOHOLS (to date) Ketones Aldehydes epoxides I OH-OH 1. BH3 OH 2. NaOH/H2O2 H+/H 2O OH OH 1. OsO4](https://reader033.vdocuments.site/reader033/viewer/2022060909/60a385df4e450d21dc256e69/html5/thumbnails/6.jpg)
Comparison ofReducing Agents
• LiAlH4 is stronger.• LiAlH4 reduces more
stable compoundswhich are resistant toreduction. =>
![Page 7: METHODS FOR THE SYNTHESIS OF ALCOHOLS (to date) · METHODS FOR THE SYNTHESIS OF ALCOHOLS (to date) Ketones Aldehydes epoxides I OH-OH 1. BH3 OH 2. NaOH/H2O2 H+/H 2O OH OH 1. OsO4](https://reader033.vdocuments.site/reader033/viewer/2022060909/60a385df4e450d21dc256e69/html5/thumbnails/7.jpg)
Alcohols, carbonyl compounds and carboxylic acids:OXIDATION
R C HR"
R'
R C HH
R'
R C HH
H
R C OHR"
R'
R C OHH
R'
R C OHH
H
PCC
X
R C
O
R'
R C
O
H
X
PCC
NH
R C
O
OH
CrO3Cl-
Primary alcohol
Secondary alcohol
Tertiary alcohol
Aldehyde
Ketone
Carboxylic acid
Na2Cr2O7/
H2SO4
Oxidation: loss of H2, addition of O or O2, addition of X2 (halogens)
Na2Cr2O7/
H2SO4