a)
Interpretation:
A mechanism using curved arrows, for the conversion of alcohol given into the corresponding alkene by treating with POCl3, is to be proposed. The regiochemistry of the elimination is also to be explained.
Concept introduction:
The dehydration of alcohols to
To propose:
A mechanism using curved arrows, for the conversion of alcohol given into the corresponding alkene by treating with POCl3 is to be proposed.
To explain:
The regiochemistry of the elimination reaction.
b)
Interpretation:
A mechanism using curved arrows, for the conversion of alcohol given into the corresponding alkene by treating with POCl3, is to be proposed. The regiochemistry of the elimination is also to be explained.
Concept introduction:
The dehydration of alcohols to alkenes in the presence of POCl3 follows E2 mechanism. The –OH group is converted into a better leaving group dichlorophosphate, –OPOCl2, when treated with POCl3. Pyridine used as solvent is also a base and it removes a proton arranged anti to the leaving group from the β carbon (requirement for E2 mechanism). The removal of the proton and –OPOCl2 occurs simultaneously in a single step to yield the alkene as the product.
To propose:
A mechanism using curved arrows, for the conversion of alcohol given into the corresponding alkene by treating with POCl3, is to be proposed.
To explain:
The regiochemistry of the elimination reaction.
c)
Interpretation:
A mechanism using curved arrows, for the conversion of alcohol given into the corresponding alkene by treating with POCl3, is to be proposed. The regiochemistry of the elimination is also to be explained.
Concept introduction:
The dehydration of alcohols to alkenes in the presence of POCl3 follows E2 mechanism. The –OH group is converted into a better leaving group dichlorophosphate, –OPOCl2, when treated with POCl3. Pyridine used as solvent is also a base and it removes a proton arranged anti to the leaving group from the β carbon (requirement for E2 mechanism). The removal of the proton and –OPOCl2 occurs simultaneously in a single step to yield the alkene as the product.
To propose:
A mechanism using curved arrows, for the conversion of alcohol given into the corresponding alkene by treating with POCl3, is to be proposed.
To explain:
The regiochemistry of the elimination reaction.
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Chapter 17 Solutions
Organic Chemistry
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