871108-91-7Relevant academic research and scientific papers
Synthetic studies on (-)-lemonomycin: An efficient asymmetric synthesis of lemonomycinone amide
Wu, Yan-Chao,Bernadat, Guillaume,Masson, Geraldine,Couturier, Cedric,Schlama, Thierry,Zhu, Jieping
, p. 2046 - 2052 (2009)
Asymmetric synthesis of lemonomycinone amide (2) was accomplished from readily accessible starting materials. Enantioselective alkylation of N-(diphenylmethylene)glycine tert-butyl ester (11) by 5-tert- butyldimethylsilyloxy-2,4-dimethoxy-3-methylbenzyl bromide (10) in the presence of Corey-Lygo's phase transfer catalyst [O-(9)-ally-N-(9-anthracenylmethyl) cinchonidium bromide, 0.1 equiv] afforded, after chemoselective hydrolysis of the imine function (THF/H2O/AcOH), the substituted L-tert-butyl phenylalanate 13 in 85% yield. A Pictet-Spengler reaction of 14 with benzyloxyacetaldehyde (15) provided the 1,3-cisdisubstituted tetrahydroisoquinoline 16 in 85% yield as a single diastereomer. Coupling of hindered secondary amine 16 with amino acid 9 was accomplished under carefully controlled conditions to furnish the amide 22, which was in turn converted to hemiaminal 24. A hafnium triflate catalyzed conversion of hemiaminal to α-amino thioether followed by a silver tetrafluoroborate promoted intramolecular Mannich reaction of 26 afforded the tetracycle 27 in excellent overall yields. Debenzylation of 27 [Pd(OH)2, H2, MeOH, 0°C], removal of N-Boc function (aqueous 3 N HCl, MeOH/H2O), and oxidation of hydroquinone to quinone [(NH4)2Ce(NO 3)6, H2O, rt] afforded the lemonomycinone amide 2 in 76% yield over three steps
NOVEL SAFRAMYCIN ANALOGS AS THERAPEUTIC AGENTS
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Page/Page column 44, (2008/06/13)
The present invention is directed to saframcyin analogs that are useful in the treatment of cancer. Pharmaceutical compositions and processes for preparing these compounds are also disclosed.
NOVEL SAFRAMYCIN ANALOGS AS THERAPEUTIC AGENTS
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Page/Page column 50, (2010/02/15)
The present invention is directed to saframcyin analogs that are useful in the treatment of cancer. Pharmaceutical compositions and processes for preparing these compounds are also disclosed.
