title: Enantioselective total synthesis of tricyclic myrmicarin alkaloids.
abstract: [reaction: see text] An enantioselective gram-scale synthesis of a key dihydroindolizine intermediate for the preparation of myrmicarin alkaloids is described. Key transformations in this convergent approach include a stereospecific palladium-catalyzed N-vinylation of a pyrrole with a vinyl triflate, a copper-catalyzed enantioselective conjugate reduction of a beta-pyrrolyl enoate, and a regioselective Friedel-Crafts reaction. The synthesis of optically active and isomerically pure samples of (4aR)-myrmicarins 215A, 215B, and 217 in addition to their respective C4a-epimers is presented.
authors.affiliation: Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA. mavassag@mit.edu
authors.forename: Mohammad
authors.initials: M
authors.lastname: Movassaghi
authors.forename: Alison E
authors.initials: AE
authors.lastname: Ondrus
mesh_terms: D000470:Alkaloids / Q000138:chemical synthesis* / Q000737:chemistry*; D003500:Cyclization; D006575:Heterocyclic Compounds, 3-Ring / Q000737:chemistry*; D015394:Molecular Structure; D013237:Stereoisomerism
chemical_list: D000470:Alkaloids; D006575:Heterocyclic Compounds, 3-Ring; C512230:myrmicarin