Select the correct group(s) of reagent(s) used in the following conversions:

Options

A. a.`I implies dil. HNO_(3)`, `II implies Na_(2)Cr_(2)O_(7)//H_(2)SO_(4)`
`III implies KMnO_(4)//NaOH`, `IV implies PbO_(4)//overset(ɵ)(O)H, H_(3)O^(o+)`
B. b.`I implies dil. HNO_(3), II implies KMnO_(4)//H^(o+)`
`III implies KMnO_(4)//NaOH`,
`IV implies TsCl+ acidic KMnO_(4)+H_(2)O`
C. c.`I implies KMnO_(4)//NaOH, II implies Na_(2)Cr_(2)O_(7)//H^(o+)`,
`III implies KMnO_(4)//overset(ɵ)(O)H, IV implies dil. HNO_(3)`
D. d.`I implies CrO_(3)//MeCOOH, II implies KMnO_(4)//overset(ɵ)(O)H`,
`III implies KMnO_(4)//H^(o+), IV implies dil. HNO_(3)`

Answer

A, B

Explanation

(I) `implies` Dilute `HNO_(3)` oxidies only one `(Me-)` group tp `(-COOH)` group.
(II) `implies` EWG, e.g., `(-NO_(2))` group makes the benzene ring stable, so either acidic `KMnO_(4)` or acidic `K_(2)Cr_(2)O_(7)` can be used to oxidise the `(Me-)` group to `(-COOH)` group.
III `implies (-I)` effect of `Cl` makes the benxene ring stable, so oxidising agent such as alkaline `KMnO_(4)` or acidic `K_(2)Cr_(2)O_(7)` can be used to oxidise the `(Me-)` group to `(COOH)`.
IV `implies EDG (+R)` effect of `(-OH)` group makes the benzene ring unstable, so either `(-OH)` has to be protected by tosylation using `TsCl` and then oxidation of `(Me-)` group to `(-COOH)` group by acidic `KMnO_(4)` is carried out followed by hydrolysis or by using a very mild O.A. such as `PbO_(2)//overset()(O)H, H_(3)O^(o+)`. So the answers are `(a)` and `(b)`.