The structure of the product derived from the reaction of a dihydropyridine derivative with phenylsulfinylallene has been clarified by a single crystal X-ray analysis and the formation mechanism is discussed on the basis of the reaction-path calculations by semiempirical and ab initio molecular orbital methods.
In connection with the pericyclic reaction of 3, 5-dimethylpyridine N-oxide with N-substituted maleimides, the structure of a 1, 5-sigmetropy product was determined by the X-ray crystallographic method. In the reaction of 2-alkylpyridine N-oxides with N-substituted maleimides, we have isolated a series of 1 : 3 ene reaction products of a new type.The primary exo cycloadducts readily transform into the endo 1, 5-sigmatropic rearrangement products, which again react with two molecules of N-substituted maleimide to give the 1 : 3 ene reactio products. The observed reaction behavior and plausible reaction pathways are discussed in terms of frontier molecular orbital considerations.
Pericyclic Reaction of Ketenes with Cascade Reaction Products of Pyridine N-Oxides and Dipolarophiles. X-Ray Structures of the Adducts and Formation Mechanism
The structures of the adducts derived from the reactions of substituted ketenes with dihydropyridine derivatives have been clarified by single crystal X-ray analyses and the formation mechanism is discussed on the basis of the reaction-path calculations by semiempirical and density functional theory (DFT) molecular orbital methods.