... 17. a) Han, C. H.; Chen, Y. L.; Tzeng, CC Nucleosides & Nucleotides 1991, 10, 1391. b) Lee, K. H.; Chen, YL; Huang B. R.; Tzeng, CC Nucleosides & Nucleotides 1991, 10, 1407. c). Wang, EC; Chen, H. Y.; Tzeng, CC J. Chin. ... Received 9/13/93 Accepted 1/19/94