NEET 2024 · ChemistryPrevious Year Question

Identify the correct reagents that would bring about the following transformation (an alkene converted, via the anti-Markovnikov primary alcohol, to an aldehyde):

Answer: (A) (A) (i) $BH X_{3}$ , (ii) $H X_{2} O X_{2}$ / $OH X^{-}$ , (iii) PCC. \textbf{Answer:} (A) (i) $BH X_{3}$ , (ii) $H X_{2} O X_{2}$ / $OH X^{-}$ , (iii) PCC \textbf{Solution:} Hydroboration-oxidation ( $BH X_{3}$ then $H X_{2} O X_{2}$ / $OH X^{-}$ ) adds water across the double bond with anti-Markovnikov regiochemistry, giving the primary alcohol $R - CH X_{2} - CH X_{2} OH$ .

NEET 2024 Chemistry question — Identify the correct reagents that would bring about the following transformation (an…

A.(A) (i) $BH X_{3}$ , (ii) $H X_{2} O X_{2}$ / $OH X^{-}$ , (iii) PCC✓
B.(B) (i) $BH X_{3}$ , (ii) $H X_{2} O X_{2}$ / $OH X^{-}$ , (iii) alk. $KMnO X_{4}$ , (iv) $H X_{3} O X^{+}$
C.(C) (i) $H X_{2} O$ / $H X^{+}$ , (ii) PCC
D.(D) $H X_{2} O$ / $H X^{+}$

Correct Answer

(A) (A) (i) $BH X_{3}$ , (ii) $H X_{2} O X_{2}$ / $OH X^{-}$ , (iii) PCC

Solution & Explanation

\textbf{Answer:} (A) (i) $BH X_{3}$ , (ii) $H X_{2} O X_{2}$ / $OH X^{-}$ , (iii) PCC \textbf{Solution:} Hydroboration-oxidation ( $BH X_{3}$ then $H X_{2} O X_{2}$ / $OH X^{-}$ ) adds water across the double bond with anti-Markovnikov regiochemistry, giving the primary alcohol $R - CH X_{2} - CH X_{2} OH$ . PCC (pyridinium chlorochromate) is a mild oxidant that oxidises the 1 $^{\circ}$ alcohol only as far as the aldehyde, without over-oxidation to the carboxylic acid. Option (B) would oxidise further ( $KMnO X_{4}$ ) to the acid; options (C) and (D) give the wrong (Markovnikov) alcohol or no oxidation. Hence (A).

🎯

43,000+ questions in हिंदी & English · one-tap toggle

Practice NEET 2024 Chemistry — free, with instant solutions

43,000+ NEET questions solved step-by-step, chapter-wise, in the MedicNEET app.

Open →📚Practice all NEET Chemistry PYQs chapter-wise →💡Don't get it? Learn the Alcohols, Phenols And Ethers concepts →

← Chemistry Q15 Chemistry Q17 →

More NEET PYQ solutions

ChemIdentify the suitable reagent for the following conversion: C6H5COOCH3 -> C6H5CHO (methyl benzoate to benzaldehyde)ChemThe correct order of decreasing acidity of the following aliphatic acids is ChemThe major product of the following reaction is: 4-oxo-4-phenylbutanenitrile C6H5-CO-CH2-CH2-CN is treated with (i) CH3MgBr (excess) and then (ii) H3O+.ChemOut of the following complex compounds, which compound will have the minimum conductance in solution?ChemWhich of the following are paramagnetic? A. [NiCl4]^2- B. Ni(CO)4 C. [Ni(CN)4]^2- D. [Ni(H2O)6]^2+ E. Ni(PPh3)4 ChemThe correct order of the wavelength of light absorbed by the following complexes is: A. [Co(NH3)6]^3+ B. [Co(CN)6]^3- C. [Cu(H2O)4]^2+ D. [Ti(H2O)6]^3+ChemThe correct order of decreasing basic strength of the given amines is: (N-ethylethanamine = (C2H5)2NH; ethanamine = C2H5NH2; N-methylaniline = C6H5NH(CH3); benzenamine/aniline = C6H5NH2)ChemPredict the major product P in the following sequence of reactions. The starting material is 1-methylcyclopent-1-ene: (i) HBr, benzoyl peroxide; (ii) KCN; (iii) Na(Hg)/C2H5OH P (major). The structures of the options (A)-(D) are shown in the image below:

More: All NEET 2024 Chemistry PYQs · NEET Chemistry PYQs · All NEET PYQs · Previous year papers