Answer the following: Identify the compounds [A], [B] and [C] in the following reaction sequence…
Answer the following:
(a)
Identify the compounds [A], [B] and [C] in the following reaction sequence:
$\text{CH}_3\text{C}\equiv\text{N} \xrightarrow[\text{H}_2\text{O}]{\text{SnCl}_2/\text{HCl}} [\text{A}] \xrightarrow[\text{H}_2\text{O}]{\text{CH}_3\text{MgBr}} [\text{B}] \xrightarrow{\text{Acidified } \text{K}_2\text{Cr}_2\text{O}_7} [\text{C}]$
(b)
Identify the compounds [A], [B] and [C] in the following reaction sequence:
$\text{H}-\text{C}\equiv\text{C}-\text{H} \xrightarrow{\text{Hg}^{2+}/\text{H}_2\text{SO}_4} [\text{A}] \xrightarrow{[\text{O}] / \text{K}_2\text{Cr}_2\text{O}_7 + \text{H}_2\text{SO}_4} [\text{B}] \xrightarrow{\text{PCl}_5} [\text{C}]$
(c)
Write chemical equations to convert the following:
(1) Acetone to propene
(2) Benzaldehyde to cinnamic acid
Answer
Answer (a)
AIWritten by AI (gemini) - it can contain mistakes.
[A] is acetaldehyde, $\text{CH}_3\text{CHO}$ (Stephen reduction)
[B] is propan-2-ol, $\text{CH}_3\text{CH(OH)CH}_3$
[C] is acetone, $\text{CH}_3\text{COCH}_3$
Answer (b)
AIWritten by AI (gemini) - it can contain mistakes.
[A] is acetaldehyde, $\text{CH}_3\text{CHO}$ (hydration of ethyne)
[B] is acetic acid, $\text{CH}_3\text{COOH}$ (oxidation)
[C] is acetyl chloride, $\text{CH}_3\text{COCl}$ (reaction with $\text{PCl}_5$)
Answer (c)
AIWritten by AI (gemini) - it can contain mistakes.
(1) Acetone to propene:
$\text{CH}_3\text{COCH}_3 \xrightarrow{\text{LiAlH}_4} \text{CH}_3\text{CH(OH)CH}_3 \xrightarrow{\text{conc. } \text{H}_2\text{SO}_4,\ 443\text{ K}} \text{CH}_3\text{CH}=\text{CH}_2 + \text{H}_2\text{O}$
(2) Benzaldehyde to cinnamic acid (Perkin reaction):
$\text{C}_6\text{H}_5\text{CHO} + (\text{CH}_3\text{CO})_2\text{O} \xrightarrow{\text{CH}_3\text{COONa},\ \Delta} \text{C}_6\text{H}_5\text{CH}=\text{CHCOOH} + \text{CH}_3\text{COOH}$
From ISC 2027 Specimen Chemistry Paper 1, question 19(ii).