Poonsakdi PloypradithRachel Kirk KaganSomsak RuchirawatChulabhorn Research InstituteCalifornia State University ChicoThe Institute of Science and Technology for Research and Development, Mahidol University2018-06-212018-06-212005-06-24Journal of Organic Chemistry. Vol.70, No.13 (2005), 5119-5125002232632-s2.0-20844458108https://repository.li.mahidol.ac.th/handle/20.500.14594/16441Four solid-supported reagents have been utilized in the multistep synthesis of lamellarins. The use of Amberlyst A-26 Br3- and polymer bound pyridine hydrobromide perbromide (PVPHP) for keto α-bromination of the less studied ortho-substituted acetophenone derivatives selectively furnished the corresponding monobromination products (phenacyl bromide derivatives), which were used directly in condensation reactions with benzyldihydroisoquinoline mediated by Amberlyst A-26 NaCO 3-. The 2H-pyrrole carbonates subsequently underwent intramolecular Friedel-Crafts transacylation followed by lactonization to provide the lamellarin skeleton. Alternatively, Amberlyst A-26 NaCO 3- effectively served as base in condensation reaction of benzyldihydroisoquinoline with α-nitrocinnamate derivatives to provide the corresponding 2-ethoxycarbonyl pyrroles, which smoothly underwent O-debenzylation reaction followed by lactonization to furnish the lamellarin skeleton. The novel Amberlyst-15 mediated lactonization reactions effectively combined the otherwise two separate steps into a single transformation. © 2005 American Chemical Society.Mahidol UniversityChemistryArticleSCOPUS10.1021/jo050388m