Schroth, Werner; Dunger, Simona; Billig, Frank; Spitzner, Roland; Herzschuh, Rainer; Vogt, Almut; Jende, Thomas; Israel, Gunter; Barche, Jens; Stroehl, Dieter; Sieler, Joachim Tetrahedron, 1996 , vol. 52, # 39 p. 12677 - 12698