Explanation:
a. Vanillin(4-hydroxy-3-methoxybenzaldehyde):
In its structure hydroxl group will be present on para position of the benzaldehyde ring and methoxy group on meta position.
b. Thymol (2-isopropyl-5-methylphenol):
In its structure isopropyl group will be present on ortho position of the phenol ring and methyl group on meta position.
c. Carvacrol (5-isopropyl-2-methylphenol):
In its structure isopropyl group will be present opposite to methyl group which is present ortho position in a phenol ring.
d. Eugenol (4-allyl-2-methoxyphenol):.
In its structure allyl group will be present on para position of the phenol ring and methoxy group on ortho position.
e. Gallic acid (3,4,5-trihydroxybenzoic acid):
In its structure hydroxyl group will be present on both meta positions and on para position of the benzoic acid ring.
f. Salicyl alcohol (o-hydroxybenzyl alcohol):
In its structure, [tex]-CH_2OH[/tex] group is linkedto benzene ring and in respect to that hydroxyl group is present at ortho position of the ring.
