Ring opening of activated cyclopropanes with NIS/NaN3: synthesis of C-1 linked pseudodisaccharides
作者:Shrutisagar Dattatraya Haveli、Sudipta Roy、Vibha Gautam、Ketan C. Parmar、Srinivasan Chandrasekaran
DOI:10.1016/j.tet.2013.11.005
日期:2013.12
NIS/NaN3 mediated ringopening of various donor–acceptor cyclopropanes has been investigated. The study shows the necessity of the donor oxygen lone pair in such ringopening reactions. This methodology has been utilized in the synthesis of C-1 linked pseudodisaccharides through the use of click chemistry.
已经研究了NIS / NaN 3介导的各种供体-受体环丙烷的开环。研究表明在这种开环反应中需要供体氧孤对。通过使用点击化学,该方法已用于合成C-1连接的假二糖。
Synthesis of Unnatural C-2 Amino Acid Nucleosides Using NIS-Mediated Ring Opening of 1,2-Cyclopropane Carboxylated Sugar Derivatives
作者:Srinivasan Chandrasekaran、Shrutisagar Haveli、Sudipta Roy
DOI:10.1055/s-0028-1087545
日期:2009.2
We have developed a general and efficient method for the stereoselective construction of pyrimidine-based pyranosyl C-2 amino acid nucleosides using NIS-mediated ringopening of 1,2-cyclopropanated sugar derivatives. This methodology has been successfully extended to the synthesis of furanosyl nucleosides, Which have potential applications in the development of novel, nontoxic antifungal therapeutics
An efficient methodology for the synthesis of 2-C-branchedglyco-aminoacid derivatives by diastereoselective ringopening of 1,2-cyclopropanecarboxylatedsugars in good yields is reported. [reaction--see text]
A stereoselective methodology was developed for the construction of C-spiro-glycosides in two steps involving bromonium ion activated solvolytic ring opening of sugar derived 1,2-cyclopropanecarboxylates followed by a one-pot dehydrohalogenation, intramolecular hetero-Michael addition (IHMA) and ester hydrolysis. The obtained spirocyclic lactols were further converted to enantiomerically pure spirolactones.
theory: 1,2‐Cyclopropanecarboxylated sugars were used as glycosyl donors for the first time in the synthesis of 2‐C‐branched oligo(glyco–aminoacid)s (OGAAs; see scheme) decorated with α‐amino acids. The method was applied to an acceptor‐reactivity‐based stereo‐ and regioselective glycosylation reaction towards the preparation of several disaccharide‐derived glyco–aminoacid derivatives.