Acrolein: 2-Propenal

The case of a, -unsaturated caAonyl compounds is analogous to that of 1,3-dienes, in that stereoelectronic factors favor coplanaiity of the C=C—C=0 system. The rotamers that are important are the s-trans and s-cis conformations. Microwave data indicate that the s-trans form is the only conformation present in detectable amounts in acrolein (2-propenal). The equilibrium distribution of s-trans and s-cis conformations of a,fi-unsatuiated ketones depends on the extent of van der Waals interaction between substituents. Methyl vinyl ketone has minimal unfavorable van der Waals repulsions between substituents and exists predominantly as the s-trans conformer ... 

Acrolein (2-propenal) is an unsaturated aldehyde with a disagreeable odor. When pure, it is a colorless liquid, that is highly reactive and polymerizes easily if not inhibited. 

Propellant 12, see Dichlorodifluoromethane Propenal, see Acrolein Prop-2-en-l-al, see Acrolein 2-Propenal, see Acrolein Propenamide, see Acrylamide 2-Propenamide, see Acrylamide Propenenitrile, see Acrylonitrile 2-Propenenitrile, see Acrylonitrile Propene oxide, see Propylene oxide Propenitrile, see Acrylonitrile... 

ACROLEIN AND DERIVATIVES. Acrolein (2-propenal), C3H4O, is the simplest unsaturated aldehyde (CH2=CHCHO). The primary characteristic of acrolein is its high reactivity due to conjugation of the carbonyl group with a vinyl group. More than 80% of the refined acrolein that is produced today goes into the synthesis of methionine. Much larger quantities of crude acrolein are produced as an intermediate in the production of acrylic acid. More than 85% of the acrylic acid produced worldwide is by the captive oxidation of acrolein. 

The same explanation can be used to rationalize the outcome of the reaction of isoprene (2-methyl-1,3-butadiene) with acrolein (2-propenal). In this case, though, because the diene is 2-substituted, Cldiene is nucleophilic and combines with C2dienophiie to give the observed product. 

In 1954, Kosak (2170) pnblished a list of components reported to be present in tobacco smoke. His list is shown in Table 111-1. The aldehydes listed included formaldehyde, acetaldehyde, acrolein (2-propenal), butyraldehyde (bntanal), benzaldehyde, and 2-fnraldehyde. In several instances, Kosak qnestioned whether the analytical data reported were snffi-cient to define nneqnivocally the identity of the smoke component. The ketones listed by Kosak included 3-pentanone (diethyl ketone), 4-heptanone (di-n-propyl ketone), 17-tritri-acontanone (dipalmityl ketone), 2,3-butanedione (biacetyl), and higher ketones. 

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