Synthesis and Biological Activity Of Unsymmetrical Bis-Steroidal Pyrazines Related to the Cytotoxic Marine Natural Product Cephalostatin 1
摘要:
A mild, high-yielding synthesis of symmetrical steroidal pyrazines was achieved from the dimerization of 2-amino-3-ketosteroids, which were produced in situ from the triphenylphosphine-water reduction of the corresponding alpha-azido ketone. 2-Azidocholestan-3-one gave the dimeric steroidal pyrazine very cleanly, and two known dimeric pyrazines based on androstanone were also made using this methodology. Both C-2-symmetric geometric isomers of the dimeric steroidal pyrazine derived from cholestane were prepared by reaction of 2,3-diaminocholestane with cholestane-2,3-dione. A route to unsymmetrical bis-steroidal pyrazines was based on the observation that alpha-acetoxy ketones react with alpha-amino oximes directly with no need for oxidation of intermediate dihydropyrazines. Heating either 2 beta,17 beta-dihydroxyandrostan-3-one diacetate or 2 beta,17 beta-dihydroxyhecogenin-3-one diacetate with 2-amino-3-methoxyiminocholestane in toluene at 145 degrees C gave the corresponding unsymmetrical pyrazine in moderate yield. Five of the steroidal pyrazines were evaluated in the National Cancer Institute's new in vitro, disease-oriented antitumor screen, but none showed sufficient activity to warrant in vivo investigation.
Synthesis and Biological Activity Of Unsymmetrical Bis-Steroidal Pyrazines Related to the Cytotoxic Marine Natural Product Cephalostatin 1
摘要:
A mild, high-yielding synthesis of symmetrical steroidal pyrazines was achieved from the dimerization of 2-amino-3-ketosteroids, which were produced in situ from the triphenylphosphine-water reduction of the corresponding alpha-azido ketone. 2-Azidocholestan-3-one gave the dimeric steroidal pyrazine very cleanly, and two known dimeric pyrazines based on androstanone were also made using this methodology. Both C-2-symmetric geometric isomers of the dimeric steroidal pyrazine derived from cholestane were prepared by reaction of 2,3-diaminocholestane with cholestane-2,3-dione. A route to unsymmetrical bis-steroidal pyrazines was based on the observation that alpha-acetoxy ketones react with alpha-amino oximes directly with no need for oxidation of intermediate dihydropyrazines. Heating either 2 beta,17 beta-dihydroxyandrostan-3-one diacetate or 2 beta,17 beta-dihydroxyhecogenin-3-one diacetate with 2-amino-3-methoxyiminocholestane in toluene at 145 degrees C gave the corresponding unsymmetrical pyrazine in moderate yield. Five of the steroidal pyrazines were evaluated in the National Cancer Institute's new in vitro, disease-oriented antitumor screen, but none showed sufficient activity to warrant in vivo investigation.
Steroide, 32. Stereospezifische Darstellung stickstoffhaltiger Steroide aus Aziridinen und vicinalen Azidoalkohol‐methansulfonaten
作者:Kurt Ponsold、Dieter Klemm
DOI:10.1002/cber.19721050827
日期:1972.8
3α-(6a) und 2β.3β-Diamino-cholestan (3a) werden aus den entsprechenden trans-diaxialen Azidoalkohol-sulfonaten (4, 1) über die cis-Diazide 5 und 2 synthetisiert. Das trans-diaxiale 2β.3α-Diamino-cholestan (9a) wird durch Ringöffnung von 2α.3α- und 2β.3β-Imino-cholestan und nachfolgende Reduktion der erhaltenen Azido-amine 8a und 11a dargestellt. Die Umsetzung der isomeren N-Benzoyl-aziridine 12 und 14 mit
2α.3α-(6a)和2β.3β-二氨基胆甾醇(3a)werden aus den entsprechenden trans -diaxialen Azidoalholhol-sulfonaten(4,1,)顺式-Diazide 5和2合成。Das反式双轴2β.3α-二氨基胆甾醇(9a)与durchRingöffnungvon2α.3α-和2β.3β-Imino-cholestanund nachfolgende Reduktion der halhaltenen Azido-amine 8a和11a dargestellt。死于异构体的N-苯甲酰基-氮丙啶12和14 mit Natriumazid wird untersucht。
Synthesis and Biological Activity Of Unsymmetrical Bis-Steroidal Pyrazines Related to the Cytotoxic Marine Natural Product Cephalostatin 1
作者:Clayton H. Heathcock、Stephen C. Smith
DOI:10.1021/jo00101a052
日期:1994.11
A mild, high-yielding synthesis of symmetrical steroidal pyrazines was achieved from the dimerization of 2-amino-3-ketosteroids, which were produced in situ from the triphenylphosphine-water reduction of the corresponding alpha-azido ketone. 2-Azidocholestan-3-one gave the dimeric steroidal pyrazine very cleanly, and two known dimeric pyrazines based on androstanone were also made using this methodology. Both C-2-symmetric geometric isomers of the dimeric steroidal pyrazine derived from cholestane were prepared by reaction of 2,3-diaminocholestane with cholestane-2,3-dione. A route to unsymmetrical bis-steroidal pyrazines was based on the observation that alpha-acetoxy ketones react with alpha-amino oximes directly with no need for oxidation of intermediate dihydropyrazines. Heating either 2 beta,17 beta-dihydroxyandrostan-3-one diacetate or 2 beta,17 beta-dihydroxyhecogenin-3-one diacetate with 2-amino-3-methoxyiminocholestane in toluene at 145 degrees C gave the corresponding unsymmetrical pyrazine in moderate yield. Five of the steroidal pyrazines were evaluated in the National Cancer Institute's new in vitro, disease-oriented antitumor screen, but none showed sufficient activity to warrant in vivo investigation.