Question

$R - CH _{2}- CH _{2} OH$ can be converted into $RCH _{2} CH _{2} COOH$. The correct sequence of the reagents is

• A. $KCN$ and $H ^{+}$
• B. $PBr , KCN$ and $H _{2}$
• C. $PBr _{3}, KCN$ and $H ^{+}$
• D. $HCN , PBr _{3}$ and $H ^{+}$

Answer 1

Answer: (C)

$R - CH_2 - CH_2OH \xrightarrow{PBr_3}R - CH_2CH_2Br \xrightarrow{KCN}$

$R - CH_2CH_2CN \xrightarrow[{H_2O}]{H^+} R - CH_2CH_2 -COOH$

This is called upgradation reaction.