Enantioselective Total Synthesis of Desbromoarborescidines A–C and the Formal Synthesis of (<i>S</i>)‑Deplancheine

Starting from Boc-protected tryptamine and (<i>S</i>)-tetrahydro-5-oxo-2-furancarboxylic acid, facile enantioselective total synthesis of desbromoarborescidines A–C and the formal synthesis of (<i>S</i>)-deplancheine have been accomplished via a common intermediate (<i>S</i>)-indolo­[2,3-<i>a</i>]­quinolizine. Synthesis of enantiomerically pure (<i>S</i>)-acetoxyglutarimide, stereoselective reductive intramolecular cyclization, hydroxyl group-assisted in situ <i>N</i>-Boc-deprotection, selective deoxygenation of the xanthate ester, and lactam hydrolysis followed by an appropriate exchange of nitrogen regioselectivity in intramolecular cyclization were the decisive steps