Intramolecular Hydro-<i>N</i>-alkylation of Hydrazones and Oxime Ethers: Synthesis of Novel D-Secoestrone Isoquinuclidines via Domino 1,5-Hydride Shift/Cyclization
The direct transformation of a benzylic C(sp3)–H bond into a C–N bond from steroidal hydrazones 10b, 10f–l and oximeethers 28b–d under the action of a stoichiometric amount of Lewis acid is reported. The mechanism of functionalization to give novel types of isoquinuclidine derivatives 25b, 25f–l and 32b–d is assumed to involve an intramolecular domino 1,5-hydride transfer/cyclization sequence. Azomethine