Helional

Say itHEE-lee-uh-nal

Wet cyclamen, green hay, crisp melon, fresh ozone.

What it is: A molecule made in a lab.
When you smell it: Heart: the first hours.
What perfumers do with it: Adds transparent, watery air to florals and marine accords; blends especially well with muguet and cyclamen
Worth knowing: Tropional and Aquanal are other sellers' names for this same molecule.
Known in: Diorella (Dior, 1972)
Rules: Limited. IFRA 51 caps it near 2.6% in fine fragrance
Also called: Tropional (Vigon); Aquanal; ocean propanal; heliopropanal

Not on the label of any of the 232 perfumes read so far.

Sources