Reactions of Conjugated Systems like Dienes

You may use these summaries and problems but you may NOT download them for use at another site, nor may you charge for access to them. Copyright Linda M. Sweeting 1997

The following example reactions are organized by type, with references to text chapters. Links within these summaries (which may show up as boxes around reagents) will provide further information about the reagents and their other reactions. Return to Graphical Reaction Summary menu for other functional group choices.

Reactions are shown for one mole of reagent; in general, the reaction of two moles of reagent can readily be predicted from the reactions of alkenes.

+

Mechanism! Not stereospecific.
1,4-addition dominates when at equilibrium, i.e. under thermodynamic control, at room temperature or higher.
1,2-addition dominates when not at equilibrium, i.e. under kinetic control, below 0oC.
McMurry 14.5, Fessenden 16.2A, Schmid 19.8 - 19.9
+
Mechanism!
1,4-addition dominates when at equilibrium, i.e. under thermodynamic control, at room temperature or higher.
1,2-addition dominates when not at equilibrium, i.e. under kinetic control, below 0oC.
Other acids react the same way to give alcohols, bromides, etc.
McMurry 14.5, Fessenden 16.2A, Schmid 19.8 - 19.9
+
Diels Alder Reaction. Stereospecific! This is a reaction of the alkene and diene, not the C=O; it works best when the alkene is electron-deficient, so the C=O's function is to withdraw electrons
McMurry 14.8, Fessenden 16.3A-C, Schmid 19.12 (NOT 19.10 and 19.11)
Other reactions of alkenes also occur. Hydrogenation is not readily controllable as the original conjugated diene is less reactive than the alkene product.
To reactions of alkenes or back to the main graphical reaction menu.
Last update Feb 10, 1999