3- Hydroxypropionaldehyde

Acrolein reacts slowly in water to form 3-hydroxypropionaldehyde and then other condensation products from aldol and Michael reactions. Water dissolved in acrolein does not present a hazard. The reaction of acrolein with water is exothermic and the reaction proceeds slowly in dilute aqueous solution. This will be hazardous in a two-phase adiabatic system in which acrolein is suppHed from the upper layer to replenish that consumed in the lower, aqueous, layer. The rate at which these reactions occur will depend on the nature of the impurities in the water, the volume of the water layer, and the rate... 

Propanediol is a colorless liquid that boils at 210-211°C. It is soluble in water, alcohol, and ether. It is an intermediate for polyester production. It could be produced via the hydroformylation of ethylene oxide which yields 3-hydroxypropionaldehyde. Flydrogenation of the product produces 1,3-propanediol. 

The penultimate enzyme in the pathway, glycerol dehydratase (E. C. 4.2.1.30), catalyzing the dehydration of glycerol to 3-hydroxypropionaldehyde, is a vitamin B12-dependent, cyanocobalamin-containing enzyme, which employs a radical... 

Doleyres, Y., Beck, P., Vollenweider, S. and Lacroix, C. 2005. Production of 3-Hydroxypropionaldehyde Using a Two-Step Process with Lactobacillus Reuteri. Appl. Microbiol. Biotechnol., 68,467-474. 

Vancauwenberge, J.E., Slininger, P.J. and Bothast, RJ. 1990. Bacterial Conversion of Glycerol to 3-Hydroxypropionaldehyde. Appl. Environ. Microbiol., 56, 329-332. 

Benzyloxycarbonylamino)acetamido]-3-hydroxypropionaldehyde hydrate (12) gave 6-hydroxymethyl-3,4,5,6-tetrahydro-2 (I //l-pyrazinone (13) (Pd/C, MeOH, H2) 50 atm, 20°C, 24 h 96%).1061 2-(2-Aminoethylamino)ethanol gave piperazine (14) (Cu—A1203 catalyst, continuous flow, 200°C 95%).1064 Also other examples.1330,1641... 

Few dials have been obtained by this method. An example is the preparation of 2-isopropyl-1,3-butanediol from excess methylmagnesium iodide and 2-isopropyl-3-hydroxypropionaldehyde (72%). ... 

C5H10O2 2,2-dimethyl-3-hydroxypropionaldehyde 597-31-9 409.77 35.287 2 5634 C5H11CIO 3-chloro-2-methyl-2-butanol 21326-62-5 414.65 35.748 1,2... 

Oxidation of aqueous solutions (10% wlw ) of 3-hydroxypropionaldehyde (HPA) in the presence of 3 % Pd/C catalysts at pH 8 produces malonic acid. Complete conversion, with 96.7 % yield, was achieved with large amounts of catalyst (33% wlw Pd relative to HPA) [91]. Starting from 3-hydroxypropionic acid the malonic acid selectivity was 95.4 % at 97 % conversion. In the presence of 5 % Pt/C catalysts (28 % wlw Pt with respect to HPA), aqueous solutions (10% wlw) of 3-hydroxypropionaldehyde were oxidized into 3-hydroxypropionic acid, an intermediate used to prepare pharmaceutical and agricultural products. The best yield, obtained without pH regulation, was 92.9% at 97.2% conversion [92]. 

All the chemical processes for the preparation of PDO have a similar intermediate, 3-hydroxypropionaldehyde, which is chemically synthesized using different chemical catalysts with a variety of feedstocks, and then is reduced to PDO using hydrogen... 

This process consists of a three-step reaction propylene is oxidized to acrolein, aaolein is hydrated to 3-hydroxypropionaldehyde, which then is reduced to PDO (Amtz 1991). 

The key step in this process is the hydratation of acrolein, where various by-products are generated, and the quality of PDO is dependent on the hydroxylation of acrolein. So a high-performance catalyst which can selectively hydrate acrolein to form 3-hydroxypropionaldehyde is important for the industrial application of this process. Meanwhile, the instability and toxicity of acrolein are negative lactors in this process (Fig. 1). 

This route consists of a two-step reaction. Firstly, ethylene oxide is carbonylated with carbon monoxide and hydrogen to form 3-hydroxypropionaldehyde. 3-Hydroxypropionaldehyde is purified and then reduced to PDO by hydrogen. The chemical catalysts used in the route are important for the selectivity and yield of the products, especially in the first reaction. The availability on a large scale with low cost and stability of ethylene oxide merits the use of this route, but the high cost of equipment and difficulty in preparing the catalysts hamper its industrial applications (Slaugh et al. 1995, 2(X)1). 

Formaldehyde and acetaldehyde easily undergo aldol-condensation reactions to form 3-hydroxypropionaldehyde using KOH as a catalyst, and then aluminum isopropoxide catalyzes the reduction of 3-hydroxypropionaldehyde to PDO after removal of KOH via an ion-exchange resin. This route was firstly reported in a patent from India. The formaldehyde and acetaldehyde feedstocks used in this method... 

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