Ciklički aldehidi bez druge kisikove skupine (osim benzaldehida)
Aldehydalkoholy, aldehydétery, aldehydfenoly a aldehydy s ďalšou kyslíkatou funkciou [okrem etylvanilínu (3-etoxy-4-hydroxybenzaldehyd) a vanilínu (4-hydroxy-3-metoxybenzaldehyd)]