Synthesis of Cytostatic Tetradecacyclic Pyrazines and a Novel Reduction-Oxidation Sequence for Spiroketal Opening in Sapogenins
摘要:
Aiming towards spiroketal-modified artificial cephalostatin molecules, two orthogonal approaches were investigated. First, the introduction of 17-O-functionality into hecogenin derivatives with a closed spiroketal moiety was accomplished by different remote-oxidation procedures. These allowed the synthesis of tetradecacyclic artificial cephalostatin molecules with improved tumor-inhibiting properties. Second, a novel reduction-oxidation pathway for spiroketal opening in sapogenins was discovered, which should provide the basis for a broad access towards spiroketal-modified building blocks for cephalostatins.
Synthesis of Cytostatic Tetradecacyclic Pyrazines and a Novel Reduction-Oxidation Sequence for Spiroketal Opening in Sapogenins
摘要:
Aiming towards spiroketal-modified artificial cephalostatin molecules, two orthogonal approaches were investigated. First, the introduction of 17-O-functionality into hecogenin derivatives with a closed spiroketal moiety was accomplished by different remote-oxidation procedures. These allowed the synthesis of tetradecacyclic artificial cephalostatin molecules with improved tumor-inhibiting properties. Second, a novel reduction-oxidation pathway for spiroketal opening in sapogenins was discovered, which should provide the basis for a broad access towards spiroketal-modified building blocks for cephalostatins.