72352-82-0Relevant articles and documents
Synthesis, absolute configuration, and enantiomeric enrichment of a cruciferous oxindole phytoalexin, (S)-(-)-spirobrassinin, and its oxazoline analog
Suchy,Kutschy,Monde,Goto,Harada,Takasugi,Dzurilla,Balentova
, p. 3940 - 3947 (2007/10/03)
Stereochemical studies of a cruciferous oxindole phytoalexin, (S)-(-)-spirobrassinin [(-)-4], and its oxazoline analogue, spirooxazoline (11), were carried out. Racemic spirobrassinin [(±)-4] was synthesized by SOCl2- or MsCl-mediated cyclization of dioxibrassinin [(±)-8]. Treatment of (3-hydroxyoxindol-3-yl)methylammonium chloride [(±)-9] with CSCl2 and subsequent methylation of the obtained spirooxazolidinethione (±)-10 afforded spirooxazoline [(±)-11]. Enantioresolution of (±)-4 and (±)-11 was achieved by derivatization with (S)-(-)-1-phenylethyl isocyanate (12), chromatographic separation of diastereomeric amides 13, 14 or 15, 16, and their cleavage with CH3ONA. Absolute configuration of the stereogenic center in natural (S)-(-)-4 was derived from the exciton, calculated via CD methods, and unequivocally confirmed by X-ray crystallographic analyses of 1-[1′S,4′R-(-)-camphanoyl] derivatives [(-)-19 and (-)-20] of (+)- and (-)-4. Novel enantiomeric enrichment phenomena of 4 and 11 were discovered during their chromatographic separations under achiral HPLC conditions. Screening of antifungal activity against the fungus Bipolaris leersiae revealed no significant dependence of this activity on absolute configuration.
Syn-isomer of 3,7-disubstituted-3-cephem-4-carboxylic acid compounds and processes for the preparation thereof
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, (2008/06/13)
Preparation of pharmaceutical composition comprising, treatment of human and animal diseases with, and compound of, 3,7-disubstituted-3-cephem-4-carboxylic acid.
