Английская Википедия:Heptanal
Heptanal or heptanaldehyde is an alkyl aldehyde. It is a colourless liquid with a strong fruity odor, which is used as precursor to components in perfumes and lubricants.[1]
Production
The formation of heptanal in the fractional distillation of castor oil[2] was already described in 1878. The large-scale production is based on the pyrolytic cleavage of ricinoleic acid[3] (Arkema method) and on the hydroformylation of 1-hexene with rhodium 2-ethylhexanoate as a catalyst upon addition of some 2-ethylhexanoic acid (Oxea method):[1][4]
Heptanal naturally occurs in the essential oils of ylang-ylang (Cananga odorata), clary sage (Salvia sclarea), lemon (Citrus x limon), bitter orange (Citrus x aurantium), rose (Rosa) and hyacinth (Hyacinthus).[5]
Properties
Heptanal is a flammable, slightly volatile colorless liquid of pervasive fruity to oily-greasy odor,[6] which is miscible with alcohols[5] and practically insoluble in water.[7] Because of its sensitivity to oxidation, heptanal is filled under nitrogen and stabilized with 100 ppm hydroquinone.[8]
Heptanal forms flammable vapor-air mixtures. The compound has a flash point of 39.5 °C.[7] The explosion range is between 1.1% by volume as the lower explosion limit (LEL) and 5.2% by volume as the upper explosion limit.[7] Its ignition temperature is 205 °C.[7]
Uses
Heptanal can be used for the production of 1-heptanol via hydrogenation:
The oxidation of heptanal with oxygen in the presence of a rhodium catalysts leads at 50 °C to heptanoic acid in 95% yield.[9] Heptanal reacts with benzaldehyde in a Knoevenagel reaction under basic catalysis with high yield and selectivity (> 90%) to jasminaldehyde,[10][1] which is mostly used in fragrances for its jasmine-like aroma as a cis/trans isomer mixture.[11]
alpha-Pentylzimtaldehyd (Jasminaldehyd) durch Aldolkondensation von Benzaldehyd mit Heptanal
A by-product of the given reaction is the unpleasant rancid smelling (Z)-2-pentyl-2-nonenal.[12] When good reasons are givenШаблон:Clarify, heptanal can be converted into (Z)-2-pentyl-2-nonenal virtually quantitatively in the presence of aqueous boric acid upon azeotropic removal of water.[13]
2-Pentyl-2-nonenal durch Selbstkondensation von Heptanal
Full hydrogenation provides the branched primary alcohol 2-pentylnonan-1-ol, also accessible from the Guerbet reaction from heptanol.[14]
References
- ↑ 1,0 1,1 1,2 Шаблон:Ullmann
- ↑ F. Krafft, Distillation of castor oil, under educed pressure, Analyst, 3, 329a (1878).
- ↑ A. Chauvel, G. Lefebvre, Petrochemical Processes: Technical and Economic Characteristics, Band 2, S. 277, Editions Technip, Paris, 1989, Шаблон:ISBN.
- ↑ Deutsche Patentschrift DE 102007053385, Verfahren zur Herstellung von Aldehyden, Erfinder: A. Fischbach et al., Anmelder: Oxea Deutschland GmbH, veröffentlicht am 20. Mai 2009.
- ↑ 5,0 5,1 G. A. Burdock, Fenaroli’s Handbook of Flavor Ingredients, Fifth Edition, 2005, CRC Press, Boca Raton, Fl., Шаблон:ISBN.
- ↑ Шаблон:Cite journal
- ↑ 7,0 7,1 7,2 7,3 Шаблон:GESTIS
- ↑ Acros Organics, Sicherheitsdatenblatt, Heptaldehyde, stabilized, überarb. am 19. November 2012.
- ↑ Deutsche Patentschrift DE 10010771, Verfahren zur Herstellung aliphatischer Carbonsäuren aus Aldehyden, Erfinder: H. Springer, P. Lappe, Anmelder: Celanese Chem Europe GmbH, veröffentlicht am 3. Mai 2001.
- ↑ Шаблон:Cite journal
- ↑ Riechstofflexikon A, alpha-Amylzimtaldehyd, Letzte Änderung am 4. August 2000.
- ↑ J. M. Hornback, Organic Chemistry, 2nd edition, S. 886, Thomson Brooks/Cole, 2006, Шаблон:ISBN.
- ↑ Шаблон:Cite journal
- ↑ G.H. Knothe: Lipid Chemistry, Guerbet Compounds Шаблон:Webarchive, AOCS Lipid Library, 22 December 2011.
