764-39-6

Usage

Chemical Properties

2-Pentenal has a pungent, green, apple, orange, tomato odor.

Occurrence

Reported found in aqueous orange essence (trans-form); as a flavor component in cognac oil, in Chrysocoris stolli, in tomato aroma, in the autooxidation of cod liver oil, in peas, as a flavoring component of reverted soybean oil, in salmon oil, in potato chips during storage, in butterfat fishy flavor. Also reported found in strawberry, cooked potato, wheat bread, parmesan cheese, butter, caviar, fatty fish, cooked beef, tea, peanuts, peas, trassi, mango, raspberry, pumpkin, Bourbon vanilla, oysters and loganberry.

Preparation

By treating β-phenoxyacrolein with secondary amines, Grignard reagent and active methylene compounds; by heating 1-ethoxy-1,3-pentadiene with H3PO4 at 80°C; from cis- and trans-but-2-ene-1,4-diol and SOCl2, followed by treatment of the chloroalcohol with methyl magnesium bromide and final oxidation with MnO2.

Definition

ChEBI: An enal consisting of pent-2-ene having an oxo group at the 1-position

Safety Profile

Poison by intraperitoneal route. Mutation data reported. Whenheated to decomposition it emits acrid smoke and irritating fumes.

InChI:InChI=1/C5H8O/c1-2-3-4-5-6/h3-5H,2H2,1H3

Upstream product

• 33498-40-7 1,1-diethoxy-pent-2-ene 
• 1576-96-1 (E)-2-penten-1-ol 
• 25073-25-0 trans-2-pentene-1,4-diol 
• 25296-22-4 trans-1,4-dibromo-2-pentene 
• 39595-61-4 1,1,3-triethoxypentane 
• 5604-66-0 1-(2-ethoxy-cyclopropyl)-ethanol 
• 110-62-3 pentanal 
• 62084-18-8 4-pentene-2,3-diol 
• 7664-93-9 sulfuric acid 
• 591-93-5 1,4-Pentadiene 
• 62946-61-6 trans-1,2-dihydroxy-3-pentene 
• 6736-21-6 3-pentene-1,2-diol 
• 109-67-1 1-penten 
• 75-07-0 acetaldehyde 

Downstream Products

• 626-98-2 pent-2-enoic acid 
• 32670-15-8 1-Morpholino-penta-1,3-diene 
• 439590-21-3 3-ethyl-5-phenyl-4-pentenal 
• 50919-60-3 diethyl 3-methylphthalate 
• 168072-33-1 4-ethyl-2-methyl-3-pyridinecarbaldehyde 
• 1026599-91-6 3-[2'-(4,4-Dimethyl-4,5-dihydro-oxazol-2-yl)-biphenyl-4-ylmethyl]-4-ethyl-2-methyl-pyridine 
• 1026004-23-8 [2'-(4,4-Dimethyl-4,5-dihydro-oxazol-2-yl)-biphenyl-4-yl]-(4-ethyl-2-methyl-pyridin-3-yl)-methanol 
• 1026857-83-9 3-{Chloro-[2'-(4,4-dimethyl-4,5-dihydro-oxazol-2-yl)-biphenyl-4-yl]-methyl}-4-ethyl-2-methyl-pyridine 
• 126019-20-3 (1R^*,2R^*,3R^*,4S^*,5S^*)-methyl 2,4-dihydroxy-3-iodo-5-methylcyclohexanecarboxylate 
• 126019-11-2 (1R^*,2S^*,5S^*)-2-acetoxy-5-methyl-3-cyclohexene-1-carboxylic acid 
• 126019-16-7 (1R^*,2S^*,5S^*)-2-hydroxy-5-methyl-1-(4-methyl-2,6,7-trioxabicyclo<2.2.2>oct-1-yl)-3-cyclohexene 
• 126019-13-4 (1R^*,2S^*,5S^*)-2-acetoxy-5-methyl-1-(4-methyl-2,6,7-trioxabicyclo<2.2.2>oct-1-yl)-3-cyclohexene 
• 126019-12-3 (1R^*,2S^*,5S^*)-(3-methyl-3-oxetanyl)methyl 2-acetoxy-5-methyl-3-cyclohexenecarboxylate 
• 126019-25-8 (1S^*,2R^*,4S^*,5S^*,6R^*)-9(E)-<2-<(tert-butyldiphenylsilyl)oxy>-1-ethylidene>-1,5-dihydroxy-4-methyl-2-(4-methyl-2,6,7-trioxabicyclo<2.2.2>oct-1-yl)-7-oxabicyclo<4.3.0>nonane 

Relevant academic research and scientific papers

Chromium-Catalyzed Production of Diols From Olefins

Processes for converting an olefin reactant into a diol compound are disclosed, and these processes include the steps of contacting the olefin reactant and a supported chromium catalyst comprising chromium in a hexavalent oxidation state to reduce at least a portion of the supported chromium catalyst to form a reduced chromium catalyst, and hydrolyzing the reduced chromium catalyst to form a reaction product comprising the diol compound. While being contacted, the olefin reactant and the supported chromium catalyst can be irradiated with a light beam at a wavelength in the UV-visible spectrum. Optionally, these processes can further comprise a step of calcining at least a portion of the reduced chromium catalyst to regenerate the supported chromium catalyst.

Highly practical and efficient preparation of aldehydes and ketones from aerobic oxidation of alcohols with an inorganic-ligand supported iodine catalyst

Herein, we divulge an efficient protocol for aerobic oxidation of alcohols with an inorganic-ligand supported iodine catalyst, (NH4)5[IMo6O24]. The catalyst system is compatible with a wide range of groups and exhibits high selectivity, and shows excellent stability and reusability, thus serving as a potentially greener alternative to the classical transformations.

Catalytic Reactions of Homo- and Cross-Condensation of Ethanal and Propanal

Abstract: Processes of catalytic homocondensation of propanal and its cross-condensation with ethanal and methanal in the presence of aniline and amino acids have been studied. The dependence of the conversion of the reactants and selectivity of the homo/heterocondensation process on the catalyst nature and temperature has been revealed. It has been shown that the maximum acrolein selectivity is reached in the case of using benzoyl-substituted derivatives in water, with the proportion of the products of further condensation decreasing. The selectivity for the ethanal homocondensation product 2-butenal decreases simultaneously as a result of the formation of linear and branched oligomers of successive condensation.

Highly Enantioselective Synthesis of Alkylpyridine Derivatives through a Michael/Michael/Aldol Cascade Reaction

A method for the synthesis of pyridine derivatives based on a triple cascade reaction catalyzed by chiral secondary amines was developed. The resulting cyclohexenes (three C–C bonds were formed) were obtained in good yields with good diastereoselectivities and excellent enantioselectivities.

Lipid-derived aldehyde degradation under thermal conditions

Nucleophilic degradation produced by reactive carbonyls plays a major role in food quality and safety. Nevertheless, these reactions are complex because reactive carbonyls are usually involved in various competitive reactions. This study describes the thermal degradation of 2-alkenals (2-pentenal and 2-octenal) and 2,4-alkadienals (2,4-heptadienal and 2,4-decadienal) in an attempt to both clarify the stability of aldehydes and determine new compounds that might also play a role in nucleophile/aldehyde reactions. The obtained results showed that alkenals and alkadienals decomposed rapidly in the presence of buffer and air to produce formaldehyde, acetaldehyde, and the aldehydes corresponding to the breakage of the carboncarbon double bonds: propanal, hexanal, 2-pentenal, 2-octenal, glyoxal, and fumaraldehyde. The activation energy of double bond breakage was relatively low (～25 kJ/mol) and the yield of alkanals (10-18%) was higher than that of 2-alkenals (～1%). All these results indicate that these reactions should be considered in order to fully understand the range of nucleophile/aldehyde adducts produced.

Thiol-functionalized fructose-derived nanoporous carbon as a support for gold nanoparticles and its application for aerobic oxidation of alcohols in water

Gold nanoparticles supported on thiol-functionalized fructose-derived nanoporous carbon (AuNPs@thiol-Fru-d-NPS) were found to be a simple bench-top, biocompatible, recyclable and selective catalytic system for the aerobic oxidation of various types of alcohols into their corresponding aldehydes and ketones at room temperature under the environmentally friendly conditions with excellent yields. Copyright

Protective groups for crossed aldol condensations

A process for protecting aldehydes and ketones in crossed aldol condensations where both aldols possess alpha-carbon hydrogens, comprising protecting the target aldol by forming an acetal or imine with an alcohol, glycol or primary amine which may contain electron-withdrawing groups, adding a base of sufficient strength to abstract a proton from the alpha-carbon of the acetal or imine and adding the second aldol to form the salt of the saturated hydroxy addition compound, thereby minimizing by-products, waste and separation difficulties, then forming the unsaturated addition compound and decomposing the acetal or imine with dilute acid. This process having the advantage that a ketone may be added to a protected aldehyde target to produce an aldehyde as a product which was not previously possible.

The atmospheric photolysis of E-2-hexenal, Z-3-hexenal and E,E-2,4-hexadienal

The atmospheric photolysis of E-2-hexenal, Z-3-hexenal and E,E-2,4-hexadienal has been investigated at the large outdoor European Photoreactor (EUPHORE) in Valencia, Spain. E-2-Hexenal and E,E-2,4-hexadienal were found to undergo rapid isomerization to produce Z-2-hexenal and a ketene-type compound (probably E-hexa-1,3-dien-1-one), respectively. Both isomerization processes were reversible with formation of the reactant slightly favoured. Values of j(E-2-hexenal)/j(NO2) = (1.80 ± 0.18) × 10-2 and j(E,E-2,4-hexadienal)/j(NO2) = (2.60 ± 0.26) × 10-2 were determined. The gas phase UV absorption cross-sections of E-2-hexenal and E,E-2,4-hexadienal were measured and used to derive effective quantum yields for photoisomerization of 0.36 ± 0.04 for E-2-hexenal and 0.23 ± 0.03 for E,E-2,4-hexadienal. Although photolysis appears to be an important atmospheric degradation pathway for E-2-hexenal and E,E-2,4-hexadienal, the reversible nature of the photolytic process means that gas phase reactions with OH and NO3 radicals are ultimately responsible for the atmospheric removal of these compounds. Atmospheric photolysis of Z-3-hexenal produced CO, with a molar yield of 0.34 ± 0.03, and 2-pentenal via a Norrish type I process. A value of j(Z-3-hexenal)/j(NO2) = (0.4 ± 0.04) × 10-2 was determined. The results suggest that photolysis is likely to be a minor atmospheric removal process for Z-3-hexenal. the Owner Societies.

Efficient transformation of propargylic alcohols to α,β-unsaturated aldehydes catalyzed by ruthenium/water under neutral conditions

α,β-Unsaturated aldehydes were selectively obtained in high yields from propargylic alcohols in aqueous solutions using RuCpCl(PR3)2 (Cp=η5-C5H5) as a catalyst. Of the tert-phosphine ligands examined, PMe3 gave the most satisfactory results. Typically, RuCpCl(PMe3)2 (5 mol%) catalyzed the transformation of oct-1-yn-3-ol at 100°C to give 2-octenal in an isolated yield of 85% (E/Z=80/20).

Synthesis of oxygen-containing compounds from 1,4-pentadiene

1,4-Pentadiene oxidation with pinane and cumene hydroperoxides was examined. The application of crude cumene hydroperoxide was shown to yield 90% 1,2-epoxypentene-4 at an oxidant conversion of over 95%. The isomerization of 1,2-epoxypentene-4 in the vapor phase at 290-330°C on lithium phosphate was studied. The rearrangement yielded 2,4-pentadiene-1-ol and unsaturated carbonyl compounds in a nearly 1:1 ratio at an epoxide conversion of 50%. Carbonyl compounds consisted mainly of pentenals with a different double-bond position. The results of the rearrangement show that the epoxide C-O bond heterolysis takes place mainly on the allyl group side.