Enantioselective total synthesis of tricyclic myrmicarin alkaloids.
[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.
Movassaghi
Mohammad
M
Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA. mavassag@mit.edu
Ondrus
Alison E
AE
D000470:Alkaloids / Q000138:chemical synthesis* / Q000737:chemistry*; D003500:Cyclization; D006575:Heterocyclic Compounds, 3-Ring / Q000737:chemistry*; D015394:Molecular Structure; D013237:Stereoisomerism
D000470:Alkaloids; D006575:Heterocyclic Compounds, 3-Ring; C512230:myrmicarin