Melonal
Melonal is 2,6-dimethyl-5-heptenal, an aldehyde that is also known under the trade name Melonal and is used as a fragrance and as a flavor. Its odor is powerful, green, melon and cucumber.
- Type
- Sirovina
- Olfactive family
- Zeleni
- Source
- Prepared from 6-methyl-5-hepten-2-one; also isolated from Java citronella oil and reported in ginger and in lemon and lime peel oil
- Chemical class
- Aldehyde
Miris
Detaljno
Dobijanje i hemija
Način dobijanja
It can be prepared from 6-methyl-5-hepten-2-one by a Darzens reaction followed by saponification and decarboxylation. The Darzens reaction joins a ketone or aldehyde with an α-haloester in the presence of a base to form an α,β-epoxy ester. An industrial Darzens process of this kind gives the racemic aldehyde with a purity of 85%. The older process leaves a significant amount of the starting ketone in the product, and its decarboxylation needs copper powder. The starting ketone has its own intensive odor profile and may suppress the odor of the aldehyde. An improved route preferably uses sodium methoxide as base and methyl chloroacetate as the α-haloester, at a low temperature, preferably at or below -15 °C. In that route the decarboxylation can be carried out in a continuous manner and without any metal powder. It can also be made by reacting 3,7-dimethyl-1,6-octadiene with N2O in a solvent that has a proton-donating functional group. It can be isolated from Java citronella oil.
- Formula
- C₉H₁₆O
- CAS
- 106-72-9
- Izgled
- Pale yellow liquid
- Jačina mirisa
- Visok
- Trajnost
- 144 hours at 100%
- Sinonimi
- melon aldehyde, melon heptenal, dimethylheptenal, Bergamal
No IFRA Standard for the material itself (51st Amendment)
- Tačka ključanja
- 116 to 124 °C @ 100 mmHg
- Tačka paljenja
- 142 °F (61 °C) TCC
- Relativna gustina
- 0.839 to 0.850 @ 25 °C
- Indeks prelamanja
- 1.439 to 1.449 @ 20 °C
U parfemima
Melonal is used in many fragrance applications and is very important for creating melon and cucumber notes. It can lend a fresh melon note to the top or middle of fragrances. It is used as an additive in cosmetic preparations and in laundry and fabric detergents. It is also used as a flavoring agent or adjuvant. It is an intermediate for other fragrances and flavors such as 6-hydroxy-2,6-dimethylheptanal and 6-methoxy-2,6-dimethylheptanal.
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