... Chem. Ber. 1977,110, 2433-2444. 0022-2623/92/1835-0511$03.00/0 0 1992 American Chemical Society Page 2. 512 Journal of Medicinal Chemistry, 1992, Vol. 35, No. 3 Scheme I1 29 30 31 32 Krohn et al. Bn OCH, En OH En CI Bn NH, - BnO q - Roq t RO OR ...