Asymmetric Formal\nTotal\nSyntheses of (+)- and (−)-Limaspermidine\nfrom Chirally Resolved 2‑Pyrone Diels–Alder Cycloadducts\nvia Aromatic C–H Amidation and Imino-Diels–Alder Reaction

A new\nasymmetric synthetic route to (+)- and (−)-limaspermidine\nwas devised, starting with chirally resolved enantiomerically pure\n2-pyrone Diels–Alder cycloadducts. This route utilizes intramolecular\nPd-catalyzed aromatic C–H amidation and imino-Diels–Alder\nreactions to construct the key indoline and indolizidine subunits\nonto the central cyclohexane core, allowing the straightforward formal\ntotal syntheses of both (+)- and (−)-limaspermidine.