Read the passage carefully and answer the Questions.
Aldehydes and ketones are important organic compounds prepared mainly by oxidation of alcohols. Primary alcohols give aldehyde and secondary alcohols yield ketones. Aldehydes can also be formed by partial reduction of acid chlorides, reduction of esters or by Gattermann-Koch reaction. Ketones are prepared via Friedel-Craft's acylation, hydration of alkyne and reaction of Grignard's reagent with nitriles. Chemically, aldehydes and ketones are reactive in nature due to the carbonyl group and undergo nucleophilic addition reactions. Aldehydes are more reactive than ketones and can be oxidized to carboxylic acids, while both can be reduced to alcohols or hydrocarbons and exhibit condensation reaction.
The correct IUPAC name of Vanillin is
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → 4-Hydroxy-3-methoxybenzaldehyde
In naming a substituted benzaldehyde, the –CHO group is the principal group and is part of the parent name (benzaldehyde), so the ring carbon carrying it is C-1. The ring is then numbered to give the other substituents the lowest locants, and the prefixes are written in alphabetical order.
Vanillin, the flavour of vanilla beans (\( \ce{C8H8O3} \)), is benzaldehyde with a methoxy group (–\( \ce{OCH3} \)) at C-3 and a hydroxyl group (–OH) at C-4, the position para to –CHO. The locants 3 and 4 are fixed by the structure. Of the two prefixes, “hydroxy” (h) comes before “methoxy” (m) in the alphabet, so the name is 4-hydroxy-3-methoxybenzaldehyde.