Hanessian, Stephen; Reddy, Gurijala V.; Huynh, Hoan K.; Jingwen, Pan; Pedatella, Silvana; Ernst, Beat; Kolb, Hartmuth C. Bioorganic and Medicinal Chemistry Letters, 1997, vol. 7, # 21 p. 2729 - 2734 doi: 10.1016/S0960-894X(97)10077-4