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Org. Synth. 1952, 32, 5
DOI: 10.15227/orgsyn.032.0005
ACROLEIN ACETAL
[Acrolein diethyl acetal]
Submitted by J. A. VanAllan1
Checked by T. L. Cairns and R. E. Benson.
1. Procedure
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%); nD25 1.398–1.407 (Note 3).
2. Notes
1. Refluxing causes the formation of some resinous material. The solution remains warm for about 1.5 hours after mixing.
2. The column described by Pingert2 is suggested.
3. This reaction appears to be of general application; crotonaldehyde diethyl acetal is formed in 68% yield; b.p. 145–147°; nD25 1.409. (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°; nD25 1.419.
3. Discussion
These have been reviewed previously.2,4 The procedure described above is an adaptation of a method reported in a German patent.5 It has been claimed that the reaction of acrolein with ethanol in the presence of hydrochloric acid2 produces a mixture of substances from which no acrolein acetal can be isolated.6 More recently it has been reported7 that acrolein acetal is formed in 62% yield from acrolein and ethanol in the presence of p-toluenesulfonic acid.

References and Notes
  1. Eastman Kodak Company, Rochester, New York.
  2. Org. Syntheses, 25, 1 (1945).
  3. Helferich, Ger. pat. 404,256 (1924) [Frdl., 14, 228 (1921–1925)].
  4. Org. Syntheses Coll. Vol. 2, 17 (1943).
  5. Schmidt, Ger. pat. 553,177 (1932) [Frdl., 19, 229 (1932)].
  6. Hall and Stern, Chem. & Ind. (London), 1950, 775.
  7. Weisblat, Magerlein, Myers, Hanze, Fairburn, and Rolfson, J. Am. Chem. Soc., 75, 5893 (1953).

Appendix
Chemical Abstracts Nomenclature (Collective Index Number);
(Registry Number)

ethanol (64-17-5)

hydrochloric acid (7647-01-0)

Acrolein (107-02-8)

sodium carbonate (497-19-8)

ammonium nitrate

Ethyl orthoformate

Acrolein acetal

Acrolein diethyl acetal (3054-95-3)

crotonaldehyde diethyl acetal

ethyl orthosilicate

Tiglylaldehyde diethyl acetal (51786-74-4)

p-toluenesulfonic acid (104-15-4)