Enantiomerically pure N-substituted alpha-(2-exo-hydroxy-10-bornylsulfinyl)maleimides 1 have been synthesized diastereoselectively, and these dienophiles undergo Diels-Alder reactions readily with furan to give the corresponding cycloadducts with high diastereoselectivity.
Arai, Yoshitsugu; Matsui, Makoto; Fujii, Akihito, Journal of the Chemical Society. Perkin transactions I, 1994, # 1, p. 25 - 40