39163-52-5Relevant academic research and scientific papers
Unsaturated aldehydes as alkene equivalents in the Diels-Alder reaction
Taarning, Esben,Madsen, Robert
supporting information; experimental part, p. 5638 - 5644 (2009/05/30)
A one-pot procedure is described for using α,β-unsaturated aldehydes as olefin equivalents in the Diels-Alder reaction. The method combines the normal electron demand cycloaddition with aldehyde dienophiles and the rhodium-catalyzed decarbonylation of aldehydes to afford cyclohexenes with no electron-with-drawing substituents. In this way, the aldehyde group serves as a traceless control element to direct the cycloaddition reaction. The Diels-Alder reactions are performed in a diglyme solution in the presence of a catalytic amount of boron trifluoride etherate. Subsequent quenching of the Lewis acid, addition of 0.3% of [Rh(dppp)2Cl] and heating to reflux achieves the ensuing decarbonylation to afford the product cyclohexenes. Under these conditions, acrolein, crotonaldehyde and cinnamaldehyde have been reacted with a variety of 1,3-dienes to afford cyclohexenes in overall yields between 53 and 88%. In these transformations, the three aldehydes serve as equivalents of ethylene, propylene and styrene, respectively.
Relationships between structure of some cyclohexene derivatives and attractiveness for the males of Ceratitis capitata
Guiotto,Rodighiero,Fornasiero
, p. 95 - 100 (2007/10/11)
Derivatives of 3 cyclohexene 1 carboxaldehyde variously substituted with methyl and phenyl groups at the 3, 4 and 6 positions, the corresponding 3 cyclohexene 1 methanol derivatives and their acetates were prepared and the relationships between their structure and their attractiveness for Ceratitis capitata males was investigated. Activity almost disappeared in the alcoholic derivatives, while some of the aldehydes and the acetates showed slight to strong attractiveness. Introduction of methyl or phenyl groups at the 3, 4 and 6 positions caused alteration of activity; the bulky phenyl group at position 6 caused loss of attractiveness in all cases.
