JEE Advanced levelSingle correct optionDifficulty 3 of 3co033
Ethanoyl chloride is treated with (X) lithium dimethylcuprate (CHX3)X2CuLi at 195 K and with (Y) excess CHX3MgBr followed by HX3OX+. The organic products X and Y are respectively
A2-methylpropan-2-ol and propanone
Bpropanone and 2-methylpropan-2-ol
Cpropanone and propan-2-ol
Dethanal and propan-2-ol
Answer: B
The Gilman reagent is not reactive enough to attack the product ketone, so it stops at CHX3COCHX3. A Grignard reagent attacks the ketone as well, so two methyl groups are added to give (CHX3)X3COH.