a) The structure of vanillin (4-hydroxy-3-methoxybenzaldehyde)
The given compound is vanillin. Its IUPAC name is 4-hydroxy-3-methoxybenzaldehyde. The root word in the name is benzaldehyde which indicates that the structure contains a benzene ring with an aldehyde functional group at first carbon atom. The functional groups that are attached to the longest chain are called substituents and they are written as prefixes in alphabetical order. The substituent present at the third carbon atom is methoxy group and that present at the fourth carbon atom is hydroxyl group. Therefore, the structural formula for the given aldehyde can be written as follows.
b) The structure of thymol (2-isopropyl-5-methylphenol)
The given compound is thymol. Its IUPAC name is 2-isopropyl-5-methylphenol. The root word in the name of the compound is phenol. It indicates that the structure consists of a benzene ring with hydroxyl functional group at the first carbon atom. The substituent present at the second carbon atom is isopropyl group and that present at the fifth carbon atom is methyl group. Therefore, the structural formula for the given compound can be shown as follows.
c) The structure of carvacrol (5-isopropyl-2-methylphenol)
The given compound is carvacrol. Its IUPAC name is 5-isopropyl-2-methylphenol. The root word ‘phenol’ in the name indicates that the structure contains a benzene ring with a hydroxyl functional group at first carbon atom. The isopropyl group is attached to the fifth carbon atom and methyl group is attached to the second carbon atom. Therefore, the structural formula for the given compound can be shown as follows.
d) The structure of eugenol (4-allyl-2-methoxyphenol)
The given compound is eugenol. Its IUPAC name is 4-allyl-2-methoxyphenol. The root word is phenol, which indicates that the structure contains a benzene ring with a hydroxyl functional group at the first carbon atom. The substituent present at the second carbon atom is methoxy group and that present at the fourth carbon atom is allyl group. Therefore, the structural formula for the given compound can be written as follows.
e) The structure of gallic acid (3,4,5-trihydroxybenzoic acid)
The given compound is gallic acid. Its IUPAC name is 3,4,5-trihydroxybenzoic acid. The root word in the name is benzoic acid which indicates that the structure contains a benzene ring with a carboxylic acid functional group at the first carbon atom. The three hydroxy groups are attached to the third, fourth and fifth carbon atom respectively. Therefore, the structural formula for the given compound can be shown as follows.
f) The structure of is salicyl alcohol (o-hydroxybenzyl alcohol)
The given compound is salicyl alcohol. Its IUPAC name is o-hydroxybenzyl alcohol. The name of the compound suggests that the compound is a benzyl alcohol with hydroxyl functional group at ortho position. Therefore, the structural formula for the given compound can be written as follows.