Asymmetric diels alder reaction using pyrazole derivatives as a chiral catalyst

N‐Acylpyrazoles (1) were promising as good dienophiles, which were easily converted into the desired carboxylic derivatives. Bis(pyrazolyl)methanes, which were derived from chiral pyrazoles, showed the activity of chiral catalyst. Particularly 10 mol% of bis(isomenthopyrazol‐1,1′‐yl)methane (8a) catalyzed enantioselectively the Diels Alder reaction up to 40 % ee by the formation of complex with Mg(ClO4)2.