title: Chemical reactivity of dihydropyrazine derivatives. Cycloaddition behavior toward ketenes.
abstract: The cycloaddition behavior of dihydropyrazines toward ketenes was investigated using single-crystal X-ray structures of the cycloadducts and density functional theory (DFT) calculation data. The reaction proceeds via a stepwise pathway involving an orientation complex prior to formation of the betaine intermediate. This is followed by electrocyclization to afford the 1 : 1 and 1 : 2 adducts bearing beta-lactam ring(s).
authors: Faculty of Pharmaceutical Sciences, Sojo University.
authors: Kazuhide
authors: K
authors: Nakahara
authors: Koki
authors: K
authors: Yamaguchi
authors: Yasuyuki
authors: Y
authors: Yoshitake
authors: Tadatoshi
authors: T
authors: Yamaguchi
authors: Kazunobu
authors: K
authors: Harano
mesh_terms: D003198:Computer Simulation; D018360:Crystallography, X-Ray; D003500:Cyclization; D007659:Ketones / Q000737:chemistry*; D008956:Models, Chemical; D008958:Models, Molecular; D015394:Molecular Structure; D011719:Pyrazines / Q000138:chemical synthesis / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: D007659:Ketones; D011719:Pyrazines