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-EBOOK>I<
- Reaction of 2-methylpropene with CH3OH in the presence of H2SO4 catalyst yieldsmethyl tert-butyl ether, CH3OC(CH3)3, by a mechanism analogous to that of acid- catalyzed alkene hydration. Write the mechanism, using curved arrows for each step.arrow_forwardDraw all of the substitution and elimination products formed from thegiven alkyl halide with each reagent: (a) CH3OH; (b) KOH. Indicate thestereochemistry around the stereogenic centers present in the products,as well as the mechanism by which each product is formed.arrow_forwardDraw the product and indicate the stereochemistry when the given alcohol is treated with each reagent: (a) HBr; (b) PBr3; (c) HCI; (d) SOCI, and pyridine.arrow_forward
- Alkenes can be hydrated to form alcohols by (1) hydroboration followed by oxidation with alkaline hydrogen peroxide and (2) acid-catalyzed hydration. Compare the product formed from each alkene by sequence (1) with those formed from (2). Q.)1-Methylcyclohexenearrow_forwardDraw the product and indicate the stereochemistry when the given alcohol is treated with each reagent: (a) HBr; (b) PBr3; (c) HCl; (d) SOCl2 and pyridine.arrow_forwardWhen 2-iodo-1,4-dimethylcyclohexane is heated in acetic acid, CH3COOH, a mixture of substitution and elimination products is obtained. Provide structures for all possible products, writing [not drawing] the name of the mechanism by which each one is formed.arrow_forward
- Draw the alkene that would react with the reagent given to account for the product formed. CH3 HCI CH3 CHCCH, ? + Či CH3 You do not have to consider stereochemistry. • You do not have to explicitly draw H atoms. • In cases where there is more than one answer, just draw one.arrow_forwardwhat is the structure of the substitution product in the following reaction and consider stereochemistry in deciding your product?arrow_forwardArrange the alkenes in each set in order of increasing rate of reaction with HI and explain the basis for your ranking. Draw the structural formula of the major product formed in each case. (a) and (b) H3CH₂CHC=CH₂ and (H3C) 2C=CHCH3arrow_forward
- 6) 25pts. Draw the structure of the major alkene product (or products) formed by treatment of each of the following haloalkanes with sodium ethoxide in ethanol. Assume the mechanism is E2 elimination. t-BuO K t-BUOH Br CH3 Eto Na F ETOH CH2CH3 CI H- Eto Na -CH2CH3 ELOH H- ČH3 Br Eto Na ELOH CH3 CI, H Eto Na CH2CH3 H3C H D ELOHarrow_forwardA 2-bromobutane react with methanol and form a enantiomeric pair of 2-methoxybutane. Draw the structures of the enntiomeric pairs of ethers.arrow_forwardAcid-catalyzed hydration of 2-Methyl-1-butene yields two alcohols. The major product does not undergo oxidation, while the minor product will undergo oxidation. Explain why, by showing the structures of theproducts.arrow_forward