Synthetics
Green hexanal smells like a grassy, green, and slightly fruity note often used as a food additive.
Luebke, William tgsc, (1984): Aldehydic dry grassy weedy green citrus fatty natural
IFF: Powerful aldehydic green note with a fresh clean impression
Pell Wall Perfumes: Floral-lily and rose, fresh-aldehydic, green, clean
Arctander says that “this aldehyde, more conspicuous by its absence from so many perfume laboratories, is used with excellent effect by the few who really enjoy experimenting with unconventional materials. in effect more versatile than methyl nonyl acetaldehyde, it creates floral-diffusive top-notes in a lily or muguet, freshness in mimosa or rose, gives clean and airy topnotes to citrus fragrances, etc.”