How do aldehydes smell?

1 Answer
Mar 14, 2016

It depends on the identity of the aldehyde. There is no collective smell.

For instance, hexyl cinnamaldehyde smells like cinnamon, cuminaldehyde smells like cumin, and anisic aldehyde generally smells sweet and floral.

Hexyl cinnamaldehyde:

https://upload.wikimedia.org/

Cuminaldehyde:

https://upload.wikimedia.org/

Anisic aldehyde:

https://upload.wikimedia.org/

I really would not say for certain that there is a set pattern for why certain aldehydes smell in a certain way. What we can say, however, is that generally the aldehydes that have a more pleasant smell are larger than those that smell worse. (Formaldehyde reeks like there's no tomorrow. I haven't smelled it, but don't try to smell it.)