Acrolein acetals

A warm solution of 3 g. of ammonium nitrate in 50 ml. of anhydrous ethanol is added to a mixture of 44 g. (52.4 ml., 0.79 mole) of acrolein and 144 g. (160 ml., 0.97 mole) of ethyl orthoformate, and the mixture is allowed to react at room temperature for 6-8 hours (Note 1). The light-red solution is filtered, 4 g. of sodium carbonate is added, and the reaction mixture is distilled from the sodium carbonate through a good column (Note 2). The fraction boiling at 120-125° is acrolein acetal and weighs 73-81 g. (72-80%) d 1.398-1.407 (Note 3).  

Refluxing causes the formation of some resinous material. The solution remains warm for about 1.5 hours after mixing. 

This reaction appears to be of general application croton-aldehyde diethyl acetal is formed in 68% yield b.p. 145-147°  

(In this preparation the amount of ethyl orthoformate used is reduced to exactly one equivalent since it distils at 142-143°. For this particular acetal, it is preferable to use ethyl orthosilicate according to Helferich.3) Tiglylaldehyde diethyl acetal is formed in 79% yield b.p. 158-160° nd 1.419. 

These have been reviewed previously.2-4 The procedure described above is an adaptation of a method reported in a German patent.6 It has been claimed that the reaction of acrolein with ethanol in the presence of hydrochloric acid 2 produces a mixture of substances from which no acrolein acetal can be isolated.6 

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Reactions with Alcohols. The addition of alcohols to acrolein may be catalyzed by acids or bases. By the judicious choice of reaction conditions the regioselectivity of the addition maybe controlled and alkoxy propionaldehydes, acrolein acetals, or alkoxypropionaldehyde acetals produced in high yields (66). 

Acrolein Acetal (ir, i) By treating acrolein with ethyl orthoformate in the presence of ammonium nitrate. Fischer and Baer, Helv. Chim. Acta i8, 514 (1935). 

Reductive cleavage of the acrolein acetal proceeds similarly to that of the benzylidene acetals. ... 

For the previous preparation of a mixed acrolein acetal and its use in an RCM reaction during callystatin A total synthesis, see Crimmins MT, King BW (1998) J Am Chem Soc 120 9084... 

The Heck coupling reaction appeared to be a route of choice to achieve the synthesis of the modified-DIOP ligands. We previously studied the palladium-catalyzed coupling of acrolein and acrolein acetals with several polyaromatic and heteroaromatic bromides either in the presence of homogeneous or heterogeneous catalytic systems (6, 7). After optimization of the reaction conditions, high conversions and selectivities were achieved except with anthracenyl derivatives (8). Based on these results, we developed the synthesis of the desired ligands. The... 

The benzotriazolyl derivative of acrolein acetal, compound 882, is lithiated, treated with chlorodiphenylphosphine, and the obtained intermediate is oxidized with hydrogen peroxide to phosphine oxide 883 (Scheme 145). The relatively acidic proton in derivative 883 is easily removed by a base, and the obtained anion adds to a carbonyl group of aldehyde or ketone. Subsequent rearrangement and elimination of the phosphorane group generates diene 884. For the derivatives of aldehydes (884, R2 = H), (E)-(E) stereoselectivity of the elimination is observed. Acidic alcoholysis of dienes 884 affords esters of P,y-unsaturated carboxylic acids 885 < 1997JOC4131>. 

Cyclic 1,2-diketones, 24 594 Cyclic acrolein acetals, 2 271 Cyclic amidine curing agents, 10 410 Cyclic amidines, 10 412 Cyclic (aromatic disulfide) oligomers, 23 712... 

The original preparation of 6-C-perfluoroalkyl-D-fructose has been reported. The first step of this synthesis is the perfluoroalkylation of acrolein acetal. The key step of the synthesis is an aldol condensation between D-3-fluoroalkylglyceraldehyde and dihydroxyacetone phosphate, with RAMA as biocatalyst (RAMA is an aldolase found in rabbit muscles) (Figure 6.43). ... 

By taking advantage of the relatively high vapor pressure of the fore-run, the acrolein acetal may be collected practically automatically, as follows. The stopcock at F is closed, and the... 

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