Crotonaldehyde: 2-Butenal

Crotonaldehyde (2-butenal) [123-73-9] M 70.1, b 104-105 , d 0.851, n 1.437. Fractionally distd under N2, through a short Vigreux column. Stored in sealed ampoules. Stabilised with 0.01% of 2,6-di-tert-butyl-p-cresol... 

Acrolein (acrylic aldehyde) 300 Crotonaldehyde (2-butenal) 280 2-Ethylcrotonaldehyde 250... 

Thiophenes can also be obtained from aldehydes, as in the synthesis of thiophene itself from crotonaldehyde (2-butenal), or the production of 2,4-dimethylthiophene from propanal both reactions are carried out at high temperatures and in the presence of catalysts (Scheme 2).5... 

Buyske et al. (564) reported butyraldehyde (butanal) and crotonaldehyde (2-butenal) in cigarette MSS. 

In testing the ciliatoxicity of cigarette MSS aldehydes to clam gill cilia, Wynder et al. (4330) reported that formaldehyde, acrolein (propenal), and crotonaldehyde (2-butenal) showed the highest toxicity. They also reported that acrolein was about twice as ciliatoxic as phenol in the clam gill cilia test [see also Wynder and Hoffmann (p. 253 in (4332)]. In addition to then-aldehyde ciliatoxicity results, Wynder et al. (4330) also noted the serious error introduced into the results obtained in their study of the ciliatoxicity of low molecular weight acids in tobacco smoke. 

Brunnemann et al. (500) detemiined several volatile aldehydes and ketones in tobacco headspace and tobacco smoke by derivatization with 2,4-dinitrophenylhydrazine. Tobacco smoke carbonyl components identified included Formaldehyde, acetaldehyde (1000 pg/cig), propionaldehyde (propanal), acrolein (propenal), isobutyraldehyde (2-methylpropanal), crotonaldehyde (2-butenal), methacrolein (2-methylpropenal), benzaldehyde (1 pg/cig), and acetone. 

Hoffmann and Hecht (1727) included formaldehyde, acetaldehyde, and crotonaldehyde (2-butenal) in their list of 43 tumorigenic components of tobacco and tobacco smoke. Their text accompanying the list plus the authors disregard of how the tumorigenicity of many of the 43 components was determined experimentally raises serious questions as to why many of the components were listed. 

Hoffmann and Hoffmann (1740, 1741) in their lists of 60 tumorigenic components of tobacco and tobacco smoke included only two aldehydes - formaldehyde and acetaldehyde. Crotonaldehyde (2-butenal) include in the 1990 Hoffmann-Hecht list (1727) was omitted from the Hoffmann-Hoffmann (1740), an omission that paralleled the 1994 OSHA list (2825). 

Rodgman and Green (3300) and Rodgman (3265) noted that formaldehyde, acetaldehyde, crotonaldehyde (2-butenal), and acrolein (propenal) were included in the majority of them (1217, 1740, 1741, 1743, 1744, 1808, 1870, 2825)... 

The gas phase hydrogenation of crotonaldehyde (2-butene-l-al from Aldrich, purity > 99.5%, used without further purification) was carried out in a quartz glass tubular reactor under atmospheric pressure. Typically, 1-10 mg of the chloride precursor were loaded into the reactor. In order to obtain a suitable catalyst bed... 

The effect of the zinc content and the reduction temperature on the characteristics and catalytic properties of bimetallic Pt-Zn catalysts supported on zeolite NaX have been analyzed. Catalysts have been characterized by TPR, XRD and XPS. Their catalytic behavior in the vapor phase hydrogenation of crotonaldehyde (2-butenal) was studied after reduction a 632 and 773 K. The presence of zinc causes a drastic decrease in catalytic activity, although the selectivity towards the hydrogenation of the C=0 bond is improved. Higher reduction temperature also improves the catalytic selectivity. The formation of Pt-Zn alloyed phases upon reduction can explain this catalytic behavior, although the contribution of a steric effect due to constraints creation in the pores of the zeolite support can not be discarded. 

Electron bombardment of a mixture of PH3 and acetaldehyde at low electron energies and low pressures causes a proton transfer reaction see 1.3.1.5.2, p. 219 [23]. CH3CHO reacts with PH3 in isopropanol or HgO in the presence of hydroquinone and PtC or CdCl2 to form (CH3CH0H)3P. Reaction of crotonaldehyde (2-butenal) yields a product with the approximate composition C32H50O9P under similar conditions. Reaction of butyraldehyde (butanal) or isovaleraldehyde (3-methylbutanal) with PH3 in the presence of PtC and hydroquinone in... 

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