title: A concise synthesis of lentiginosine derivatives using a pyridinium formation via the Mitsunobu reaction.
abstract: A four-step synthesis of (-)-lentiginosine and its epimers is described starting from 2-bromopyridine. The key step consisted of a quaternarization of a fully unprotected pyridinium-polyol unit using Mitsunobu methodology. Subsequent PtO(2)-catalyzed diastereoselective hydrogenation of the pyridinium ring proceeded smoothly and led to the expected dihydroxyindolizidines with excellent yields. This stereochemically flexible strategy has been illustrated by the concise total synthesis of non-natural products derivatives such as (-)-lentiginosine and its stereoisomers in high yields.
authors.affiliation: Laboratoire de Chimie Organique Fine et Hétérocyclique, CNRS UMR 6014, IRCOF-INSA, Université de Rouen, B.P. 08, 76131 Mont-Saint-Aignan Cedex, France corinne.fruit@insa-rouen.fr; laurent.bischoff@insa-rouen.fr.
authors.forename: Rabah
authors.initials: R
authors.lastname: Azzouz
authors.forename: Corinne
authors.initials: C
authors.lastname: Fruit
authors.forename: Laurent
authors.initials: L
authors.lastname: Bischoff
authors.forename: Francis
authors.initials: F
authors.lastname: Marsais
mesh_terms: D000470:Alkaloids / Q000138:chemical synthesis* / Q000737:chemistry; D015394:Molecular Structure; D011743:Pyrimidines / Q000737:chemistry; D013237:Stereoisomerism
chemical_list: D000470:Alkaloids; D011743:Pyrimidines; C063984:lentiginosine