Pal, Manojit; Swamy, Nalivela Kumara; Hameed, P. Shahul; Padakanti, Srinivas; Yeleswarapu, Koteswar Rao Tetrahedron, 2004, vol. 60, # 18 p. 3987 - 3997 doi: 10.1016/j.tet.2004.03.036