Question

$PhC\equiv CMe+H_{2}O\underset{H{g}^{2+}}{\overset{H_{2}S{O}_4}{\to }}?$ Identify the major product in the reaction`

• A.
  $PhC{H}_{2}C{H}_{2}CHO$
  
• B.
  $PhCOC{H}_{2}C{H}_3$
  
• C.
  $PhC{H}_{2}COC{H}_3$
  
• D.
  $PhCOCOMe$

Answer 1

The correct option is B

$PhCOC{H}_{2}C{H}_3$

Alkynes react with water in the presence of dilute sulphuric acid and mercuric sulphate at a temperature of 333K. This results in the formation of carbonyl compounds through a keto-enol tautomerization of the more substituted enol. ( except for acetylene which yields acetaldehyde ).
$PhC\equiv CMe+H_{2}O\underset{H{g}^{2+}}{\overset{H_{2}S{O}_4}{\to }}PhCOC{H}_{2}C{H}_3$