[Brook]

In a Diel's Alder reaction , is there a way to prefer one enantiomer's formation over another?

[discodermolide]

Yes there are several possibilities, chiral catalysts, chiral ligands, enzymes.

[gritch]

Ah yes there is. The term for such a reaction is asymmetric or stereospecific. I took a class on these times of reactions just last semester and I stumbled upon this little beauty from Harvard:

http://www.chem.harvard.edu/groups/myers/handouts/23_Asymmetric_Diels_Alder.pdf

It has most of the common chiral auxillaries used as well as the several common catalysis with plenty of references to read on further if anything catches your eye. Should be a good starting point.

[Dan]

The term for such a reaction is asymmetric or stereospecific.

Stereospecific is not the right term - they are stereoselective

http://www.chem.qmul.ac.uk/iupac/stereo/RS.html#50

[PhDoc]

Asymmetric Diels-Alder reactions were pioneered in part by Professor David Evans (Harvard) using L-valine derived chiral auxiliaries. You can look here for a brief article.

The Diels-Alder Reaction, Part II
http://lennoxtutoring.com/2011/11/24/the-diels-alder-reaction-part-two/

Look up the following literature references.
1. Evans, D.A.; Chapman, K.T.; Bisaha, J. J. Am. Chem. Soc. 1984, 106, 4261-4263.
2. Evans, D.A.; Chapman, K.T.; Bisaha, J. J. Am. Chem. Soc. 1988, 110, 1238-1256.

Asymmetric Diels-Alder is not limited to chelated acyl oxazolidones. Look into examples provided by Professor Hans Reich at the University of Wisconsin - Madison:

http://www.chem.wisc.edu/areas/reich/chem547/4-pericyclic%7B07%7D.htm

As mentioned by discodermolide, there are enzymatic transformations too. Enzymes are cool!

[Brook]

Thank you all for the information