title: Chiral pyridin-3-ones and pyridines: syntheses of enantiopure 2,4-disubstituted 6-hydroxy-1,6-dihydro-2H-pyridin-3-ones, 2,3-disubstituted 4-iodopyridines, and enantiopure 2,3-disubstituted 4-pyridinemethanols.
abstract: The development of an innovative method to access enantiopure 2,4-disubstituted 6-hydroxy-1,6-dihydro-2H-pyridin-3-ones starting from D-glucal via the aza-Achmatowicz transformation has been described. These highly functionalized pyridin-3-ones have been utilized for the synthesis of contiguously substituted pyridines through a rapid and efficient Et(3)N/Ac(2)O promoted cyclo-elimination, aromatization cascade, allowing the facile assembly of important pyridine-based building blocks like 2-substituted 3-acetoxy-4-iodopyridines and enantiopure 2-substituted 3-acetoxy-4-pyridinemethanols possessing benzylic stereogenic centers, whose synthesis otherwise would be tedious. The utilization of commercially available sugars as starting materials, mild reaction conditions, catalytic transfer hydrogen (CTH) of α-furfuryl azide derivatives, transfer of chiral aryl/alkyl methanols from enulosides to pyridin-3-ones and pyridines, high yields, and short reaction times are key features of this method. The utility of the method has been further exemplified by demonstrating the usage of the 2-substituted 3-acetoxy-4-iodopyridine for the construction of biologically significant molecules like 2,7-disubstituted furo[2,3-c]pyridines and 7,7'-disubstituted 2,2'-bifuro[2,3-c]pyridines.
authors.affiliation: Medicinal and Process Chemistry Division, CSIR-Central Drug Research Institute, PO Box 173, Lucknow-226001, India.
authors.forename: Irfan
authors.initials: I
authors.lastname: Husain
authors.forename: Mohammad
authors.initials: M
authors.lastname: Saquib
authors.forename: Vikas
authors.initials: V
authors.lastname: Bajpai
authors.forename: Brijesh
authors.initials: B
authors.lastname: Kumar
authors.forename: Arun K
authors.initials: AK
authors.lastname: Shaw
mesh_terms: D007469:Iodopyridones / Q000138:chemical synthesis* / Q000737:chemistry*; D015394:Molecular Structure; D011725:Pyridines / Q000138:chemical synthesis* / Q000737:chemistry*; D011728:Pyridones / Q000138:chemical synthesis* / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: D007469:Iodopyridones; D011725:Pyridines; D011728:Pyridones