Oxa-ene reaction of enols of amides with 4-phenyl-1,2,4-triazoline-3,5-dione.
The reaction of 16 enols of amides with 4-phenyl-1,2,4-triazoline-1,3-dione gave open chain adducts rather than the [2 + 2] cycloadducts with a hemiaminal moiety, both in solid state and in solution. This assignment is based on X-ray crystallography, (1)H and (13)C NMR data, and IR spectra. The suggested mechanism involves hydroxyl proton loss in a formal oxa-ene reaction. Mechanistic details and a possible alternative are discussed.
Basheer
Ahmad
A
Department of Organic Chemistry and the Lise Meitner Minerva Center for Computational Quantum Chemistry, The Hebrew University, Jerusalem 91904, Israel.
Rappoport
Zvi
Z
D000577:Amides / Q000737:chemistry*; D006860:Hydrogen Bonding; D007659:Ketones / Q000138:chemical synthesis* / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy / Q000379:methods / Q000592:standards; D015394:Molecular Structure; D012015:Reference Standards; D012996:Solutions / Q000737:chemistry; D012997:Solvents / Q000737:chemistry; D013237:Stereoisomerism; D014230:Triazoles / Q000737:chemistry*
D000577:Amides; D007659:Ketones; D012996:Solutions; D012997:Solvents; D014230:Triazoles; C053540:4-phenyl-1,2,4-triazoline-3,5-dione