Chemical reactivity of dihydropyrazine derivatives. Cycloaddition behavior toward ketenes.
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).
Nakahara
Kazuhide
K
Faculty of Pharmaceutical Sciences, Sojo University.
Yamaguchi
Koki
K
Yoshitake
Yasuyuki
Y
Yamaguchi
Tadatoshi
T
Harano
Kazunobu
K
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
D007659:Ketones; D011719:Pyrazines