Synthesis of new symmetrical bis-steroidal pyrazine analogues from diosgenin
摘要:
New symmetrical bis-steroidal pyrazine dimers that are cephalostatins/ritterazines analogues have been prepared easily from a cheap, readily available natural steroid (diosgenin). These dimers were obtained by classical, condensation of a-amino ketones in order to construct the pyrazine rings. The three dimers differ in the functionalized diosgenin: (25R)-5 alpha,6 beta-dihydroxy-5 alpha-spirosta-3-one, (25R)-4,5 alpha-epoxy-5 beta-spirosta-3,6-dione and (25R)-5 alpha-hydroxy-5 alpha-spirosta-3,6-dione respectively. (C) 2010 Elsevier Inc. All rights reserved.