Aldehyde C-14 Peach aka. Gamma Undecalactone Aroma Chemical
CAS# 104-67-6

Aldehyde C-14, commonly known as Gamma-Undecalactone or Peach Aldehyde, is a nature-identical material found in peaches and passion fruit, though it is produced commercially mainly by synthesis. The history of this material is tied to an intriguing confidentiality strategy used by the early 20th-century chemical industry. In reality, it is a lactone containing 11 carbon atoms, yet manufacturers deliberately named it Aldehyde C-14 to mislead competitors seeking to copy the formula. Existing as a clear liquid at room temperature, the introduction of this material in 1908 marked a major advance, giving perfumers a highly effective tool for recreating the most realistic and stable peach note.

Description

From an olfactory structure standpoint, Aldehyde C-14 belongs to the fruity and lactonic family, offering a sweet aroma reminiscent of ripe peach flesh, soft velvety skin, and a touch of creamy milkiness. Acting mainly from the heart note into the base note, it serves excellently as both a modifier and a foundation material. In Perfume and Flavor Chemicals, Steffen Arctander described it as having a “sweet fruity odor, characteristic of peach, extremely tenacious,” while also clarifying that “the name is a complete chemical misnomer.” In perfumery practice, this material is often paired with oakmoss, patchouli, and ionone notes to create the classic fruity chypre framework. To better control its sweetness and prevent a formula from becoming too heavy, users are commonly advised to dilute it to 10% in safe solvents such as DPG or IPM before blending.

Applications

The applications of Aldehyde C-14 extend across many fields, from fine fragrance, candles, and soap to cosmetics and flavor compositions. Unlike true aldehydic compounds, which are often subject to stricter limitations, its lactonic nature makes this material highly safe, non-phototoxic, and not subject to strict IFRA concentration restrictions. Perfumers typically use it flexibly at levels ranging from 0.1% to 2% to soften sharp floral notes or to create a distinct fruity accent. Thanks to its high safety profile and excellent substantivity, Aldehyde C-14 has become part of perfumery history, playing a central role in the legendary peach note of Mitsouko, the fragrance created by Guerlain in 1919.