Organic Chemistry
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An optically active epoxide is produced when (E)-1,2-dicyclopentylethene is epoxidized in an enantioselective manner using the Jacobsen catalyst. However, the product is optically inactive when the same conditions are utilized using (Z)-1,2-dicyclopentylethene as a substrate. Elucidate this observation.
Draw the product(s) formed when the given alkene undergoes a reaction with mCPBA.
Draw the product(s) formed when the given compound reacts with m-CPBA.
Determine the reaction's atom economy below and describe the fate of the remaining percentage of material not utilized in the major product.
Draw the products of the reaction of the given molecule with mCPBA.
Indicate the stereochemistry, and draw both enantiomers if the product is a racemic mixture.
Even though the epoxidation reaction is stereospecific, the formation of an epoxide will lead to a mixture of enantiomers while producing a chiral compound.
Why does the reaction form a racemic mixture of products?
Despite the fact that the reaction is stereospecific, the formation of an epoxide will lead to a mixture of enantiomers while producing the chiral molecule.
How can a reaction be stereospecific and still yield two enantiomers?
Rank the following alkenes with respect to relative reactivity with m-CPBA, 1 being the most reactive and 5 being the least.
To gain insight into concerted reactions, one can conceptualize them as stepwise reactions where all steps, except the slowest one, possess exceedingly small activation energies. Illustrate the hypothetical stepwise mechanism by presenting a reaction coordinate diagram for the following example.
To gain insight into concerted reactions, one can conceptualize them as stepwise reactions where all steps, except the slowest one, possess exceedingly small activation energies. Illustrate the actual concerted mechanism of the reaction through a reaction coordinate diagram.
Provide two different pathways to carry out the following reaction.
For the reaction of 3-ethyl-2-methylpent-2-ene with m-CPBA (meta-chloroperoxybenzoic acid), predict the major product.
Illustrate the product(s) that will be formed in the reactions of cis-3-hexene and trans-3-hexene with a peroxyacid. State which stereoisomers are produced, if applicable.
Provide the products for the epoxidation reactions of the following alkenes through m-chloroperoxybenzoic acid. Include stereochemistry where appropriate.
a. cis-but-2-ene
b. trans-but-2-ene
a. cis-cyclononeneb. trans-cyclononene
Provide the structure of the major product in the epoxidation reaction given below.
cis-but-2-ene + m-CPBA in chloroform
Epoxides can be synthesized from alkenes using the reagents below. Draw a mechanism for the sequence of reactions below.
Draw the product(s) when the following molecule is reacted with mCPBA. For racemic mixtures, draw both enantiomers.
The formation of an epoxide is stereospecific; this is evidence for its concertedness. If step (ii) in the given hypothetical non-concerted reaction where the original reaction is slowed down, what is the product's distribution change?
m-CPBA is a peracid with a carbonyl group. Explain how the carbonyl weakens the σ bond between the two oxygen atoms, which makes hydroxyl a better-leaving group.
Give the atom economy for the reaction shown below. Hint: Catalysts and solvents should be excluded.
Determine the alkene molecule needed to be reacted with a peroxyacid to produce the following epoxide.
(i) cyclopentene oxide
(ii) 2-isopropyloxirane
(i) Determine the alkene needed to produce the following compound:
(ii) Determine if any other epoxides would form.
(iii) Determine the absolute configuration of each asymmetric center of any other epoxide formed.
(i) Draw the alkene molecule needed to produce the following compound:
(ii) Draw any other epoxide formed in the reaction.
(iii) Assign the R and S configuration to each chiral center.
Draw the alkenes needed to react with a peroxy acid to produce the following epoxides:
(i) 2,3-diethyl-2,3-methyloxirane
(ii) 3,4-epoxy-3-ethylhexane
MMPP (magnesium monoperoxyphthalate) is a reagent used for the epoxidation of alkenes. MMPP is more stable and it may be safer to use for large-scale and industrial reactions compared to another common reagent, mCPBA (meta-chloroperoxybenzoic acid). Draw the product and the mechanism for the reaction of trans-1,2-dicyclopentylethene with MMPP.
Draw the structure of the product expected when the molecule below reacts with an excess of m-chloroperoxybenzoic acid. (Ignore stereochemistry)
Retrosynthetic analysis is the process of working backward to develop the synthesis of a new compound. Suggest an alkene and a reagent that would give the product below. Note: The alkene should not undergo rearrangement.
Determine the expected product(s) of the given reaction and specify its relative stereochemistry. If a racemic mixture is formed, draw both of the enantiomers.
Draw the expected product(s) of the reaction shown below and specify its relative stereochemistry. If a racemic mixture is produced, draw both of the enantiomers.