Evolution of a Short Route to Strychnine by Using the Samarium-Diiodide-Induced Cascade Cyclization as a Key Step
作者:Christine Beemelmanns、Hans-Ulrich Reissig
DOI:10.1002/chem.201500094
日期:2015.6.1
diastereoselective samarium diiodide‐induced cascadereaction of substituted indolyl ketones. The complexity‐generating transformation with SmI2 allows the diastereoselective generation of three stereogenic centers including one quaternary center in one step. The obtained tetra‐ or pentacyclic dihydroindole derivatives are structural motifs of many monoterpene indole alkaloids, and their subsequent transformations
stereoselectively provided a pentacyclic compound that was subsequently N‐protected and subjected to a regioselective elimination. The obtained functionalized pentacyclic product should be convertible into the alkaloid brucine by four well‐established steps. Overall, the presented report shows that functionalized tetracyclic compounds with different substituents are rapidly available with the samarium