enzyme of the mevalonate‐independent pathway of the isoprenoid biosynthesis. Using fosmidomycin as a specific inhibitor of Dxr, this enzyme was previously validated as target for the treatment of malaria and bacterial infections. The replacement of the formyl residue of fosmidomycin by spaciousacylresidues yielded inhibitors active in the micromolar range. As predicted by flexible docking, evidence was
Highly diastereoselective samarium diiodide induced cyclizations of new 3-substituted indole derivatives
作者:Christine Beemelmanns、Hans-Ulrich Reissig
DOI:10.1039/b913015b
日期:——
Herein, we describe the synthesis of new functionalized tricyclic and tetracyclic indole derivatives viasamarium diiodide induced ketyl cyclizations. The intermediate samarium organyls were either protonated using different proton sources or alkylated with various electrophiles in a highly diastereoselective manner. The obtained products were subjected to further transformations leading to synthetically interesting building blocks.
Here we summarise our results for SmI2-induced 5-exo-trig to 8-exo-trig reductive cyclisations of suitably substituted indole and pyrrole derivatives. All precursors were easily prepared by simple N-alkylation or N-acylation of indole and pyrrole derivatives with the corresponding iodo alkanones, acid chlorides or lactones. The SmI2-induced cyclisations in most cases provided tri- and tetracyclic derivatives
Biomimetic Construction of the Hydroquinoline Ring System. Diastereodivergent Enantioselective Synthesis of 2,5-Disubstituted <i>cis</i>-Decahydroquinolines
The straightforward enantioselective construction of the hydroquinoline ringsystemfrom 1,5-polycarbonyl derivatives, using (R)-phenyglycinol as a chiral latent form of ammonia, is reported. The process mimics the key steps believed to occur in nature in the biosynthesis of amphibian decahydroquinoline alkaloids. Diastereodivergent routes to enantiopure cis-2,5-disubstituted decahydroquinolines, including
19-Hydroxy carbinol analogues of PGE.sub.1 having the structure ##STR1## are disclosed as bronchodilators. Methods of preparing the analogues are also disclosed.