Question:
The incorrect statement regarding \(C\) formed in the given sequence of reactions is:
\[
CH_3CHO \xrightarrow{\text{(i) } CH_3MgBr} A
\xrightarrow{H_2O} B
\xrightarrow{PCC}
\text{dil. NaOH}
\rightarrow C
\]
The incorrect statement regarding \(C\) formed in the given sequence of reactions is:
\[
CH_3CHO \xrightarrow{\text{(i) } CH_3MgBr} A
\xrightarrow{H_2O} B
\xrightarrow{PCC}
\text{dil. NaOH}
\rightarrow C
\]
Show Hint
3-Hydroxybutanal contains one chiral carbon atom and on heating undergoes dehydration to form crotonaldehyde.
Updated On: Jun 18, 2026
- It is \(\beta\)-Hydroxybutyraldehyde
- It has no asymmetric carbons
- The IUPAC name of it is 3-Hydroxybutanal
- This on heating gives \(\alpha,\beta\)-unsaturated aldehyde
Show Solution
Verified By Collegedunia
The Correct Option is B
Solution and Explanation
Concept:
Grignard reagents add to carbonyl compounds forming alcohols. Oxidation followed by aldol reaction produces a \(\beta\)-hydroxy aldehyde.
Step 1: Formation of compound \(B\).
\[ CH_3CHO + CH_3MgBr \] gives \[ CH_3CH(OMgBr)CH_3 \] After hydrolysis, \[ B=(CH_3)_2CHOH \] which is isopropyl alcohol.
Step 2: Oxidation using PCC.
PCC converts secondary alcohol into ketone. \[ (CH_3)_2CHOH \xrightarrow{PCC} CH_3COCH_3 \] Thus the product is acetone.
Step 3: Aldol reaction.
Acetaldehyde formed initially ultimately undergoes aldol condensation under dilute NaOH conditions giving \[ CH_3CH(OH)CH_2CHO \] which is \[ \text{3-Hydroxybutanal} \] also called \[ \beta\text{-Hydroxybutyraldehyde} \]
Step 4: Check asymmetric carbon.
The carbon containing \(-OH\) is attached to \[ H,\ OH,\ CH_3,\ CH_2CHO \] all different groups. Hence it is a chiral carbon. Therefore the statement \[ \boxed{\text{It has no asymmetric carbons}} \] is incorrect.
Step 1: Formation of compound \(B\).
\[ CH_3CHO + CH_3MgBr \] gives \[ CH_3CH(OMgBr)CH_3 \] After hydrolysis, \[ B=(CH_3)_2CHOH \] which is isopropyl alcohol.
Step 2: Oxidation using PCC.
PCC converts secondary alcohol into ketone. \[ (CH_3)_2CHOH \xrightarrow{PCC} CH_3COCH_3 \] Thus the product is acetone.
Step 3: Aldol reaction.
Acetaldehyde formed initially ultimately undergoes aldol condensation under dilute NaOH conditions giving \[ CH_3CH(OH)CH_2CHO \] which is \[ \text{3-Hydroxybutanal} \] also called \[ \beta\text{-Hydroxybutyraldehyde} \]
Step 4: Check asymmetric carbon.
The carbon containing \(-OH\) is attached to \[ H,\ OH,\ CH_3,\ CH_2CHO \] all different groups. Hence it is a chiral carbon. Therefore the statement \[ \boxed{\text{It has no asymmetric carbons}} \] is incorrect.
Was this answer helpful?
0
0
Top TS EAMCET Chemistry Questions
- A, B and C are three biomolecules. The results of the tests performed on them are given below :A, B and C are respectively :
Molisch's lest Barfoed Test Biuret Test A Positive Negative Negativde B Positive Positive Negative C Negative Negative Positive - 1 mole of $H_2$ and 2 moles of $I_2$ are taken initially in a 2 litre vessel. The number of moles of $H_2$ at equilibrium is 0.2. Then the number of moles of $I_2$ and HI at equilibrium is
- The pH of a buffer containing equal molarconcentration of a weak base and its chloride ( $K_b$ for weak base = $2 \times 10^{-5}$, log 2 = 0.3) is
- Atomic radius (pm) of Al, Si, N and F respectively is
- Consider the following electrode process of a cell, $ {Cl^{-1} -> \frac{1}{2} Cl_2 + e^{-}}$ $ {[MCl + e^{-} -> M + Cl^{-} ] }$ If EMF of this cell is $-1.140\, V$ and $E^0$ value of the cell is $-0.55\,V$ at $298\,K$, the value of the equilibrium constant of the sparingly soluble salt MCl is in the order of
View More Questions
Top TS EAMCET Alcohols, Phenols and Ethers Questions
- Phenatole can be prepared from which of the following reactants?
The reagent 'X' used in the following reaction to obtain a good yield of the product is:
The \( C-O-H \) bond angle in A is \( X \) and \( C-O-C \) bond angle in B is \( Y \). What are X and Y?
IUPAC name of the following compound is:
- Two statements are given below: Statement I: The boiling points of alcohols increase with increase of branching in carbon chain.
Statement II: The solubility of alcohol decreases with increase in size of alkyl group.
View More Questions
Top TS EAMCET Questions
- A bag contains $5$ red balls, $3$ black balls and $4$ white balls are drawn at random. The probability that they are not of same colour is
- If $cosec\, \theta - \cot \theta = 2017$, then quadrant in which $\theta $ lies is
- If $a$ is a unit vector, then $| a \times \hat{ i }|^{2}+| a \times \hat{ j }|^{2}+| a \times \hat{ k }|^{2}=$
- $A$ straight line makes an intercept on the $Y$-axis twice as long as that on $X$-axis and is at a unit distance from the origin. Then the line is represented by the equations
- Let $S$ and $S'$ be the foci of an ellipse and B be one end of its minor axis. If $SBS'$ is an isosceles right angled triangle then the eccentricity of the ellipse is
View More Questions