Synthesis of Pyrrolizidines and Indolizidines by the Intramolecular Cycloaddition of Azides with Electron-Rich 1,3-Dienes. A Synthetic Equivalent of a Nitrene-Diene Cycloaddition

Article abstract of DOI:10.1021/jo00309a016

Alkyl azides were found to undergo intramolecular cycloadditions with certain 1,3-dienes to provide 2,3,5,7a-tetrahydro-1H-pyrrolizines and 3,5,6,7,8,8a-hexahydroindolizines in one operation (e.g., 12 -> 13 and 17 -> 18).The presence of an electron-donati