PROBLEM TO BE SOLVED: To provide a Diels-Alder reaction catalyst suitable for such an asymmetric Diels-Alder reaction that α-acyloxyacrolein is converted into dienophile.
SOLUTION: A toluene solution of (S)-1,1'-binaphtyl-2,2'-diamine (0.02 mmol) and Tf2NH (0.038 mmol) is prepared and toluene is distilled and removed under reduced pressure to obtain the catalyst. The obtained catalyst is dissolved in propionitrile (0.8 mL), water is added to catalyst-dissolved propionitril and then α-(cyclohexanecarbonyloxy)acrolein (0.4 mmol) is added to water-added propionitril to obtain a solution. After the obtained solution is cooled to -78°C, cyclopentadiene (1.6 mmol) is added slowly to the cooled solution and the cyclopentadiene-added solution is agitated at -78°C for 24 hours to obtain a reactive mixture. After triethylamine is added to the reactive mixture to stop the reaction, the temperature of the reaction-stopped mixture is raised to room temperature and a reaction solvent is distilled and removed under reduced pressure to obtain an exo-form body of a cyclized addition product with high enantio-selectivity.