Tandem Pseudopericyclic Reactions: [1,5]-X Sigmatropic Shift/6π-Electrocyclic Ring Closure Converting <i>N</i>-(2-X-Carbonyl)phenyl Ketenimines into 2-X-Quinolin-4(3<i>H</i>)-ones
tube in the absence of solvent. The mechanism for the conversion of these ketenimines into quinolin-4(3H)-ones has been studied by ab initio and DFT calculations, using as model compounds N-(2-X-carbonyl)vinyl ketenimines bearing different X groups (X = F, Cl, OH, SH, NH2, and PH2) converting into 4(3H)-pyridones. This computational study afforded two general reaction pathways for the first step of the