A new approach to the pseudopterosins using an arene alkylation with a γ-methylene-γ-butyrolactone
摘要:
A short and practical route to the tricyclic core of an unnatural pseudopterosin diastereoisomer is presented. Key features are an arene alkylation with a gamma -methylene-gamma -butyrolactone, viz. 10 --> 14, and an elaborate reduction sequence 14 --> 17 which both proceed diastereoselectively. (C) 2001 Elsevier Science Ltd. All rights reserved.
作者:Alan W. Johnson、Gopala Gowada、Ahmed Hassanali、John Knox、Sam Monaco、Zia Razavi、Gerald Rosebery
DOI:10.1039/p19810001734
日期:——
A range of analogues of the natural germination stimulant, strigol, for parasitic weeds of the genera Striga and Orobanche, has been prepared. Most of the products contain an α-formyl-γ-lactone (or α-formyl-γ-lactam) grouping attached through an enol-ether linkage to the 5-position of a but-2-enolide. Some have shown sufficiently high activities as to warrant large-scale field trials.
Aflatoxins Revisited: Convergent Synthesis of the ABC-Moiety
作者:Stefan Wolff、H. M. R. Hoffmann
DOI:10.1055/s-1988-27700
日期:——
After appropriate model studies, two methods of current preparative interest, namely radical-initiated 5-exo-trig cyclization and palladium/formate anion mediated intramolecular hydroarylation, were confronted and optimized for the convergent synthesis of the oxygenated ABC-moiety of aflatoxin B1.
A General Entry to Antifeedant Sesterterpenoids: Total Synthesis of (+)-Norleucosceptroid A, (−)-Norleucosceptroid B, and (−)-Leucosceptroid K
作者:Cedric L. Hugelshofer、Thomas Magauer
DOI:10.1002/anie.201407788
日期:2014.10.13
The first asymmetric total synthesis of the antifeedant terpenoids (+)‐norleucosceptroid A, (−)‐norleucosceptroid B, and (−)‐leucosceptroid K has been accomplished. This highly concise synthetic route was guided by our efforts to develop a platform for the collective synthesis of a whole family of antifeedant natural products. The synthesis features a Hauser–Kraus‐type annulation followed by an unprecedented
<i>N</i>-Phthaloylglycine-Derived Strigol Analogues. Influence of the D-Ring on Seed Germination Activity of the Parasitic Weeds <i>Striga hermonthica</i> and <i>Orobanche crenata</i>
作者:Jan Willem J. F. Thuring、Harry H. Bitter、Margreet M. de Kok、Gérard H. L. Nefkens、Annemiek M. D. A. van Riel、Binne Zwanenburg
DOI:10.1021/jf9604652
日期:1997.6.1
Several strigol analogues with modifications in the D-ring were synthesized and assayed for germination stimulatory activity of seeds of Striga hermonthica and Orobanche crenata. All of these D-ring analogues are derived from N-phthaloylglycine as the common ABC-fragment. It was concluded that the correct structure of the 2(5H)-furanone D-ring is essential to retain full biological activity.