Which of the following reagents can be used for the given reaction ?
`R-overset(O)overset(||)C-H rarr R-overset(O)overset(||)C-D`

Options

A. i. `D_(2)O //D_(3)O^(o+)` ii. `CI_(2)+AcOH` iii. `NABH_(4)//H_(2)O`
B. i. `Cl_(2)+AcOH` ii. `D_(2)O` iii. `LAH//H_(2)O`
C. i. ii. `D_(2)O` iii. `HgCl_(2)//CdCO_(3)//H_(2)O`
D. i. Base (PhLi), ii. `HgCl_(2)//CdCO_(3)-H_(2)O` iii. `D_(2)O`

Answer

C

Explanation

The `(C=O)` group is protected by converting into cyclic thioacetal and then an organometallic base like PhLi is used to generate carbanion followed by treatment with `D_(2)O` to incorporate D. Finally, the aldehyde is regenerated.