96. Acid-catalysed hydration of acraldehyde. Kinetics of the reaction and isolation of β-hydroxypropaldehyde

Abstract

A kinetic study of the acid-catalysed hydration of acraldehyde to /3-hydroxypropaldehyde (hydracraldehyde ; 3-hydroxypropan-l-al) in aqueous sulphuric acid confirms that the reaction is of the first order with respect to acraldehyde. The rate constants are independent of initial acraldehyde concentration, increase with increasing acid concentration, and are strictly proportional to Hammett's acidity function. /3-Hydroxypropaldehyde, isolated (in poor yield) from the hydration media and characterised as the 3 : 4-dinitrophenylhydrazone, dimerises spontaneously t o 4-hydroxy-2-2'-hydroxyethyl-l : 3-dioxan, the unsymmetrical structure of which is proved by acetylation and hydrolysis. Representative kinetic experiments on the dehydration of 8-hydroxypropaldehyde, using the dimer as starting material, demonstrate the ready reversibility of both the dimerisation of this aldehyde and the hydration of acraldehyde. A reversible mechanism proposed for the hydration of acraldehyde involves, as rate-determining step, the addition of a water molecule to the oxonium ion CH,:CH.CH:OH+ and the simultaneous redistribution of the charge t o give the oxonium ion TH,O*CH,CH:CH*OH which is the conjugate acid of the enol of /3-hydroxypropaldehyde. WITH the ready availability of acraldehyde on a commercial scale (see, inter alia, B.P. 569,625, 573,507, 600,454, 625,330; B.P. Appl. 22,712/39; Watson, C h e w Eng., 1947, 54, No. 12, 107), the preparation of P-hydroxypropaldehyde, an intermediate of great potential value in the solvent or the plasticiser field, has recently received considerable attention. Although P-hydroxypropaldehyde may be prepared in several ways (cf. Nef, Annalen, 1904, 335, 219; Glattfield and Sander, J . Amer. Chew. SOC., 1921, 43, 2675; Wohl and Schweitzer, Ber., 1908, 41, 3603 ; Stepanow and Schtschukin, Chem. Zepztr., 1927, I, 1167), most of the recent work has been concerned with the acid-catalysed hydration of acraldehyde (U.S.P. 2,434,110 ; German microfilmed reports P B 70,309, Frames 8214-8220 ; 73,508, Frames 7528-7537 ; and 19,417; G.P. Appl. D 89,752 IVd, Class 0, 1943).For the catalytic hydration processes described in the literature, conditions seem to be chosen rather arbitrarily and little systematic work appears to have been published in this connection.The kinetic data on the hydration of acraldehyde (Pressman and Lucas, J . Amer. Chew. SOL, 1942, 64, 1953, which are rather incomplete, are based on experiments with perchloric acid as catalyst and very dilute (about O ' O~M . ) solutions of acraldehyde, and are not, therefore, directly applicable to preparative work, A detailed kinetic study of the acid-catalysed hydration of acraldehyde was undertaken to provide fuller data, capable of such application, and an insight into the mechanism of the reaction, which has not hitherto been fully elucidated (cf. Hammett,

Effect of Magnacide ® H Herbicide Residuals on Water Quality Within Wildlife Refuges of the Klamath Basin, CA

“…The mean value corresponds to a half-life of 4.25 (SD = ±1.18) hours at a mean temperature of 21°C (SD = ±2.62). Similar kinetics for acrolein degradation have been shown previously in the laboratory where it was also demonstrated that the rate constants are independent of the initial acrolein concentrations but increase with decreasing pH (hydration) and increasing pH (condensation) (Pressman and Lucas, 1942;Hall and Stern, 1950;Bowmer and Higgins, 1976). The half-life of 46 hours (0.015 hr -1 ) calculated using dilute buffered solutions of acrolein in distilled water at 21 °C and pH 7.0 is considerably longer than the half-life observed in this and other field experiments.…”

Development and evaluation of efficient recombinant Escherichia coli strains for the production of 3‐hydroxypropionic acid from glycerol

“…3-HP was purchased from Tokyo Kasei Kogyo Co. Ltd, Tokyo, Japan (TCI America, Portland, OR). Since 3-HPA is not available commercially, it was synthesized chemically from acrolein using the method described by Hall and Stern (1950). Yeast extract (Cat.…”

Propanediols

“…1,3-Propanediol is prepared by a two-step process involving the hydrolysis of acrolein to 3-hydroxypropanal followed by hydrogenation [3,38]:…”