We have developed a highly convergent synthesis of the manumycin-type m-C7N-antibiotic nisamycin that is applicable to other members of this family of antibiotics. The synthesis features a three-step sequence to the epoxyquinol core that serves as a scaffold for the attachment of the polyene side chains. The eastern polyene side chain was constructed via a novel organozirconocene-mediated synthesis. Zirconocene methodology was also applied to the synthesis of the polyene side chains of asukamycin. The southern side chain of nisamycin was introduced via a Stille reaction that employed a vinyl bromo ketone, derived from an acid-sensitive bromo ketal. Pd-mediated coupling of the vinyl bromide with a stannyl TIPS ester gave TIPS-protected nisamycin that was readily converted to the natural product.
Organozirconocene-mediated polyene synthesis: Preparation of asukamycin and manumycin a side chains
摘要:
Hydrozirconation of a functionalized alkyne followed by transmetalation and 1,2-addition to alpha,beta-unsaturated aldehydes was used for the syntheses of the eastern side chain of asukamycin and a precursor to the southern side chain common to asukamycin and manumycin A. These routes facilitate analog preparation, and the convergent zirconocene strategy represents an alternative to stepwise Wittig condensations or Stille couplings in polyene synthesis. (C) 1997 Elsevier Science Ltd.
Organozirconocene-mediated polyene synthesis: Preparation of asukamycin and manumycin a side chains
作者:Peter Wipf、Philip D.G. Coish
DOI:10.1016/s0040-4039(97)01129-5
日期:1997.7
Hydrozirconation of a functionalized alkyne followed by transmetalation and 1,2-addition to alpha,beta-unsaturated aldehydes was used for the syntheses of the eastern side chain of asukamycin and a precursor to the southern side chain common to asukamycin and manumycin A. These routes facilitate analog preparation, and the convergent zirconocene strategy represents an alternative to stepwise Wittig condensations or Stille couplings in polyene synthesis. (C) 1997 Elsevier Science Ltd.
Total Synthesis of (±)-Nisamycin
作者:Peter Wipf、Philip D. G. Coish
DOI:10.1021/jo990413m
日期:1999.7.1
We have developed a highly convergent synthesis of the manumycin-type m-C7N-antibiotic nisamycin that is applicable to other members of this family of antibiotics. The synthesis features a three-step sequence to the epoxyquinol core that serves as a scaffold for the attachment of the polyene side chains. The eastern polyene side chain was constructed via a novel organozirconocene-mediated synthesis. Zirconocene methodology was also applied to the synthesis of the polyene side chains of asukamycin. The southern side chain of nisamycin was introduced via a Stille reaction that employed a vinyl bromo ketone, derived from an acid-sensitive bromo ketal. Pd-mediated coupling of the vinyl bromide with a stannyl TIPS ester gave TIPS-protected nisamycin that was readily converted to the natural product.