The Diels–Alder reaction of 1, 2-dihydropyridine derivatives (1-phenoxycarbonyl-1, 2- dihydropyridine 1 or 1-methoxycarbonyl-1, 2-dihydropyridine 4) with N-acryloyl (1S)-2, 10- camphorsultam (1S)-2 {or N-acryloyl (1R)-2, 10-camphorsultam (1R)-2} in the presence of Lewis acid, such as titanium tetrachloride, zirconium tetrachloride, and hafnium tetrachloride afforded the endo-cycloaddition product, 2-azabicyclo [2.2. 2] octane derivatives in good ...
