Regioselective syntheses of the indolopyridine alkaloids nauclefine, angustine, dihydroangustine and naucletine from a common intermediate
作者:Rodolfo Lavilla、Francisco Gallón、Joan Bosch
DOI:10.1039/c39950001675
日期:——
A short, flexible route for the synthesis of the title indolopyridine alkaloids consisting of the cyclization of enamide 3, followed by introduction of the requisite pyridine substituent by Pd0-catalysed reactions from the resulting pentacyclic bromo intermediate 4 is reported.
acetyl chloride induced cyclization of bromoenamide 10 affords the pentacyclic derivative 12 with high yield and regioselectivity. From this common synthetic intermediate, palladium-catalyzed reactions allow the total synthesis of indolopyridine alkaloids 1–6.