... We thank Dr. Michael Walla, Chemistry Department, University of South Carolina for the mass spectral determinations. ... AND NOTES [1] JB Hynes, A. Tomazic, A. Kumar, V. Kumar and JH Freishiem, / Heterocyclic Chem., 28 ... С. Океке, J. Heterocyclic Chem., 25, 1173 (1988). ...