Butyraldehyde, 3-hydroxy

Quaternary salts of the substances represented by tliese formulae have been prepared by Kogl, Veldstra and van der Laan as well as of the next lower homologues, the substituted butyraldehydes, and the methyl ethers of both series. Their pharmacological activities were negligible in comparison with that of muscarine, but as six stereoisomeric forms may be produced in each synthesis, the inactivity may be due to stereoisomerism, just as in the case of threonine (a-amino-)3-hydroxy-butyric acid) where West and Carter found that only the d —) form is... 

Acetaldehyde (and other aldehydes containing at least me hydrogen atom in the a-position) when treated with a small quantity of dilute sodium hydroxide solution or other basic catalyst gives a good yield of aldol (p hydroxy-n-butyraldehyde) (I), which readily loses water, either by heating the isolated aldol alone or with a trace of mineral acid, to form crotonaldehyde (II) ... 

Condensation of butanol has been carried out on alkaline earth metal oxides at 273 K (13,121). This condensation reaction yields 2-ethyl-3-hydroxy-hexanal as a main product other products, such as 2-ethyl-2-hexenal (arising from the dehydration of 2-ethyl-3-hydroxy-hexanal), n-butyl-K-butyrate (arising from the Tishchenko reaction of butyraldehyde), and 2-ethyl-3-hydroxy- -hexyl butyrate (arising from the Tishchenko reaction of 2-ethyl-3-hydroxy-hexanal), are also formed (Scheme 12). 

The order of activity per unit surface area was equal to that in the case of selfcondensation of acetone and in agreement with the order of basicity of the solids, namely, SrO > CaO > MgO. However, the authors found that the rate-determining step for aldol condensation of n-butyraldehyde is the a-hydrogen abstraction by the active sites, which are the surface ions. The differences in rate-determining step and active sites in the condensation of butyraldehyde and aldol condensation of the acetone were attributed to differences in acidity of the a-hydrogen in the two molecules. CaO was slightly more active than MgO at 273 K after a reaction time of 1 h, maximum conversions of 41% were observed with selectivities to 2-ethyl-3-hydroxy-hexanal and to the corresponding Tishchenko reaction product (2-ethyl-3-hydroxy- -hexyl butyrate) of 39.8 and 56.9%, respectively. 

These model studies permitted demonstration of metabolic a-hydroxylation of NPy by isolating 2-hydroxytetrahydrofuran as a metabolite of NPy. This was accoitplished by trapping 4-hydroxy-butyraldehyde as its 2,4-dinitrophenylhydrazone (DNP) derivative. For in vitvo studies, NPy-2,5-l C was incubated with rat liver microsomes, 02i and an NADPH generating system. After the incubation was complete, DNP reagent was added to the mixture and the products were extracted and examined by preparative TLC. A radioactive band corresponding to the DNP of 4-hydroxybutyralde-hyde was observed. This band was not present in controls in which NADPH was omitted or in which boiled enzyme was used. The mass spectrum was identical to that of a reference sairple. In addition, a minor metabolite with mass spectrum identical to that of the DNP of 2-butenal was also isolated. These results showed conclusively that NPy underwent metabolic a-hydroxylation in this in vitro system. 

Cannizzaro reaction. Aromatic aldehydes (and other aldehydes in which a-hydrogen atoms arc absent, e.g., formaldehyde, trimcthylacetaldehyde, and a-hydroxy-tso-butyraldehyde) under the influence of strong aqueous or alcoholio alkali undergo simultaneous oxidation and reduction yielding the alcohol and corresponding acid. Thus —... 

Apart from the large number of different a-keto acids which may be decarboxylated by PDC, only a few of the resulting aldehydes may be transferred to a second aldehyde molecule to form an a-hydroxy ketone [151]. Besides acetaldehyde, which is the best acylanion equivalent, propionaldehyde and butyraldehyde have been condensed to benzaldehyde by baker s yeast after decarboxylation of the corresponding a-keto acids [116,149]. 

Ethyl-trimethylolmethane or 2-Ethyl-2-Hydroxy methyl-1,3-propanediol, C2H5C(CH2OH)3 mw 134.18 wh crysts, mp 57—59°, bp l60°(5mm Hg), hyg sol in w, ale acet. Prepd by reacting butyraldehyde and formaldehyde in the presence of alkali. Used to make polyurethane resins Refs 1) Beil, not found 2) I.G. Farben-industrie A-G, BritP 484619(1938) CA 32, 7609(1938) 3) K O 1, 595(1963) ... 

Gas-liquid chromatography [1/8 in. x 6 ft, 10% diethylene glycol succinate (LAC-728) column, 70°C] of cyclobutanone (99.2% pure) revealed the presence of small amounts of methylene chloride (0.6%) and cyclobutanol (0.2%). No cleavage product, 4-hydroxy butyraldehyde, was found. The traces of water, detected by NMR spectroscopy using CD3COCD3 as a solvent, can be removed by drying over molecular sieves. 

Following the examples of Schemes 2.5 and 2.7, the target may be synthesized from butyraldehyde as shown below. An altemative is radical addition of an enantiopure 2 hydroxy 1 pentyl group (perhaps from Jacobsen hydrolytic kinetic resolution of 1,2 epoxypentane,) to the N acylhydrazone derived from 5 chloropentanal. 

Added to this are side reactions of hydrogenolysis and dehydration, yielding butanol and furan. Traces of acidity may also favor the production of butanediol and hydroxy-butyraldehyde. 

In the GAF-process, hydrogenation takes place in two steps. The fust is conducted. in an agitated reactor around 50 to 60 C, at between 1 4 and 2.10 Pa absolute, in the presence of Raney nickel and copper acetate. The butanediol obtained contains hydroxy-butyraldehyde and unsaturated compounds. It is sent to a second reactor, operating with a fixed bed, around 120 to 140 0 at between 14 and 20.106 absolute. The catalyst consists of nickel, copper and manganese deposited on alumina, in a weight ratio of 15/78/0.5. 

Katritzky et al. have prepared a-amino carbanions from tosyl methyl amines. The transformation was achieved by treatment with 2 equiv of Sml2 [82] in the presence of an electrophile (Scheme 38). In the absence of HMPA the use of iso-butyraldehyde as the electrophile gave only the amine dimer (98%). However, the addition of 5% of HMPA resulted in a 67% yield of the desired product (62%) with a minor amount of diamine (17%). The formation of the hydroxy amine probably involves a carbanion intermediate whereas coupling gives the diamine. 

Such reactions have preparative value when the halo ether is easily accessible by halogenation of an ether. For example, 2,3-dichlorodioxan and ethanol yield the cyclic acetal of glyoxal 935 and cyclic acetals of 2-chloro-4-hydroxy-butyraldehyde are formed from 2,3-dichlorotetrahydrofuran and alcohols 936, 937... 

Directed aldol condensation. House et al. have published a detailed procedure for the aldol condensation of the lithium enolate of phenylacetone with n-butyraldehyde in the presence of zinc chloride to give fhreo-4-hydroxy-3-phenyl-2-heptanone. Ether or ether-dimethoxyethane mixtures are the most suitable... 

The primary products which were quantified include 3-hexyl nitrate, 2-hexyl nitrate, n-butyl nitrate, 3-hexanone, 2-hexanone, formaldehyde, acetaldehyde, propionaldehyde, butyraldehyde and 5-hydroxy-2-hexanone. 2,5-hexanedione was quantified but is thought to be a secondary product, and 5-nitrooxy-2-hexanol was detected but reliable quantification was not possible. 

A series of alkanals and alkenals, degradation products of polyunsaturated fatty acids, were sqiarated as their dabsylhydrazine derivatives on a Cjg column (2 = 436nm) using a 60-min 40/60-> 80/20 acetonitrile/water gradient [917]. Acrolein, propionaldehyde, crotonaldehyde, butyraldehyde, 4-hydroxy-2-nonenal, malonaldehyde, fra/w-2-pentenal, hexanal, heptanal, tmns-2-octena, octanal, trans-2-nonenal, and nonanal were baseline resolved. When malonaldehyde and trans-2-hexenal were included in the set, they co-eluted with pentanal. Peak shapes were excellent and detection limits of 5 ng injected (S/N = 4) were reported. 

Some 2,4-dideoxyhexoses of type 17 (R H, OMe, Q, N3 have been made by condensation of aldehydes RCH2CHO with acetaldehyde, catalysed by 2-deoxyribose-S-phosphate aldolase in these novel en madc aldol reactions, acetaldehyde adds to the substituted aldehyde to give a 3-hydroxy-4-substituted butyraldehyde which that adds another acetaldehyde... 

However, an aldehyde containing an a-hydrogen atom undergoes an aldol condensation in the presence of a dilute base or acid. For example, two moles of acetaldehyde combine to form j6-hydroxy butyraldehyde (Eq. 2.323) ... 

Several attempts are described in the hterature to conduct n-regioselective hydroformylation of allyl alcohols (Scheme 4.33) [68, 69]. A main target is 4-hydroxy-butyraldehyde (HBA). The product can be utilized as a precursor to 1,4-butanediol (BDO) [70]. The formation of the branched aldehyde is occasionally associated with the appearance of C3 side products, such as... 

The first catalytic hydroformylation of epoxides was reported by Watanabe and coworkers in 1964 [5]. They treated propylene oxide with water gas at 80-100 C in the presence of Co2(CO)g and obtained fi-hydroxy butyraldehyde as the major product (Scheme 6.103). Apparently, HCofCO) is the active catalyst. The side products were acetone, but-2-enal, 2-methylpropenal, and 2-methylpropanal. 

The main application of poly(vinyl butyral) is as interlayers in safety glass laminates. In this application, a pure (colourless, light-stable) product with high hydroxy content (for good adhesion) is required. Such material is preferably prepared from poly(vinyl alcohol) rather than directly from poly(vinyl acetate). In a typical process, completely hydrolyzed poly(vinyl alcohol) is suspended in ethanol and then butyraldehyde and a small quantity of sulphuric acid (catalyst) are added. The mixture is heated at 80°C for 6 hours. Water is then added to the product with rapid agitation and the poly(vinyl butyral) is precipitated as granules, which are washed with alkali and dried. 

H2, CO, CO2, H2O, furan, fiirancarboxyaldehyde, methyUurans, acetone, hydroxypropanone, butenal, butanone, butanedione, levoglucosan Fixed gases (not identified), pentene, acetaldehyde, furan, propionaldehyde, acetone, acrolein, 2-methyUuran, butyraldehyde, methyl ethyl ketone, benzene, 2,5-dimethylfiiran, methyl vinyl ketone, 2,3-butanedione, toluene, crotonaldehyde, H2O, cyclopentanone, cyclooctatetraene, acetol, pyruvaldehyde, acetic add, furfural, formic acid, 5-methyl-2-furfural, furfuryl alcohol, butyrolactone, 2-hydroxy-3-methyl-3-cyclopenten-2-one, phenol, o-cresol, m-cresol, p-cresol, 2,5-dimethylphenol, 3,4-diinetfaylphenol, 5-hydroxymefhylfuifural Mainly H2O and CO 2, smaller amounts of CO, formaldehyde, methanol, acetic acid, ethanol and acetaldehyde, and very htUe tar Product fraction volatile at 25°C contains acetic acid, CO2, CO, CH4,... 

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