In epoxidation of E-2-butene, major product formed will be ________.
trans-2, 3-dimethyloxirane
Epoxidation of E-2-Butene Explained
The question asks about the major product formed during the epoxidation of E-2-butene.
Epoxidation is a reaction where an alkene is converted into an epoxide, also known as an oxirane. This is typically done using a peroxy acid, such as meta-chloroperoxybenzoic acid (m-CPBA).
The epoxidation reaction is stereospecific. This means that the stereochemistry of the starting alkene directly determines the stereochemistry of the resulting epoxide. For a concerted epoxidation using a peroxy acid:
- A Z-alkene yields a cis-epoxide.
- An E-alkene yields a trans-epoxide.
Let's consider the starting material, E-2-butene. The structure of E-2-butene is:
\[ \text{CH}_3-\text{CH}=\text{CH}-\text{CH}_3 \]In E-2-butene, the two methyl groups are on opposite sides of the double bond.
During epoxidation, the oxygen atom is added across the double bond, forming a three-membered ring containing oxygen. Because the reaction is stereospecific, the relative orientation of the substituents on the double bond (the methyl groups in this case) is maintained in the epoxide ring.
For E-2-butene (where the methyl groups are trans), the resulting epoxide will have the two methyl groups in a trans configuration relative to the plane of the epoxide ring. This product is trans-2,3-dimethyloxirane.
The reaction can be visualized conceptually as follows:
\[ \text{E-2-Butene} \xrightarrow{\text{Peroxy acid}} \text{trans-2,3-Dimethyloxirane} \]The possible products listed in the options are:
- cis-2,3-dimethyloxirane: This product would be formed from the epoxidation of Z-2-butene.
- trans-2,3-dimethyloxirane: This product is formed from the epoxidation of E-2-butene, as discussed above.
- Racemic mixture of cis and trans-2,3-dimethyloxirane: Epoxidation of a single E or Z isomer does not produce both cis and trans epoxides; it produces only one type of epoxide based on the starting stereochemistry.
- Not determinable: The product is determinable based on the stereochemistry of the starting material and the known mechanism of epoxidation.
Therefore, the major product formed in the epoxidation of E-2-butene is trans-2,3-dimethyloxirane.
Important Questions from Haloalkanes And Haloarenes
IUPAC name of neopentyl chloride is
Among the following statements, choose the correct statements.
A. SN2 reaction proceeds with stereo chemical inversion.
B. The process of conversion of Racemic mixture into enantiomer is known as Racemisation
C. A mixture containing 2 enantiomers in equal proportions is known as Racemic mixture.
D. The stereoisomers related to each other as superimposable mirror image are called enantiomers.
E. The objects which are non- superimposable on their mirror image are said to be chiral and this properly is known as chirality.
Choose the correct answer from the options given below:
Which of the following would yield a single monohalogen derivative?
The index of hydrogen deficiency (IHD) of benzene is
The given hydrocarbon is CH3 - CH2 - CH2 - CH2 - CH3
