title: Synthesis and tautomerization of hydroxylated isoflavones bearing heterocyclic hemi-aminals.
abstract: The aminomethylation of hydroxylated isoflavones with 2-aminoethanol, 3-amino-1-propanol, 4-amino-1-butanol, and 5-amino-1-pentanol in the presence of excess formaldehyde led principally to 9-(2-hydroalkyl)-9,10-dihydro-4H,8H-chromeno[8,7-e][1,3]-oxazin-4-ones 4 and/or the tautomeric 7-hydroxy-8-(1,3-oxazepan-3-ylmethyl)-4H-chromen-4-ones 5. The ratio of these tautomers was dependent on solvent polarity, electronic effects of aryl substituents in the isoflavone and the structure of the amino alcohol. NMR studies confirmed the interconversion of tautomeric forms.
authors.affiliation: Department of Molecular and Cellular Biochemistry, College of Medicine, University of Kentucky, Lexington, KY 40536-0509, USA. vitaliy.sviripa@uky.edu.
authors.forename: Mykhaylo S
authors.initials: MS
authors.lastname: Frasinyuk
authors.forename: Svitlana P
authors.initials: SP
authors.lastname: Bondarenko
authors.forename: Volodymyr P
authors.initials: VP
authors.lastname: Khilya
authors.forename: Chunming
authors.initials: C
authors.lastname: Liu
authors.forename: David S
authors.initials: DS
authors.lastname: Watt
authors.forename: Vitaliy M
authors.initials: VM
authors.lastname: Sviripa
mesh_terms: D000588:Amines / Q000737:chemistry*; D060326:Chemistry Techniques, Synthetic; D006571:Heterocyclic Compounds / Q000737:chemistry*; D006900:Hydroxylation; D007529:Isoflavones / Q000138:chemical synthesis* / Q000737:chemistry*; D007536:Isomerism
chemical_list: D000588:Amines; D006571:Heterocyclic Compounds; D007529:Isoflavones