A facile approach to polysubstituted 2-pyridones. Application to the synthesis of 3,4-disubstituted isoquinolinone and total synthesis of oxyisoterihanine
摘要:
A facile approach to polysubstituted 2-pyridones from 1-benzyl- 5,6-dialkyl-3-(4-toluenesulfonyl) pyridin-2-one was described. A new approach to 3,4-disubstituted isoquinolinone and total synthesis of oxyisoterihanine will also be reported. (C) 2007 Elsevier Ltd. All rights reserved.
One-pot facile conversion of Baylis–Hillman adduct into N-alkyl 3-(E)-alkylidene-5-substituted sulfonylpiperidine-2,6-dione. Formal synthesis of tacamonine
stepwise [3+3] strategy to N-alkyl 3-(E)-alkylidene-5-substituted sulfonylpiperidine-2,6-dione 1 used various N-alkyl α-substituted sulfonylacetamides 2 and α,β-unsaturated esters 3 as starting materials. α,β-Unsaturated esters 3 were generated by Baylis–Hillman reaction. A ring closure mechanism was proposed for the reactions. This method provides a convenient formal synthesis of tacamonine.
Stereoselective Synthesis of Constrained Azacyclic Hydroxyethylene Isosteres as Aspartic Protease Inhibitors: Dipolar Cycloaddition and Related Methodologies toward Branched Pyrrolidine and Pyrrolidinone Carboxylic Acids
[GRAPHICS]The synthesis of three vicinally substituted azacyclic carboxylic acids in enantiopure form was achieved from a common (x-amino aldehyde originating from (L)-leucine. Pyrrolidines and pyrrolidinones were elaborated from a,beta-unsaturated gamma-hydroxy-delta-amino acids via azomethine ylide 1,3dipolar addition and conjugate addition/cyclization strategies, respectively. The azacyclic amino acids were incorporated in a pseudopeptide now encompassing a hydroxyethylene isostere. Low nanomolar inhibition of BACE1, an enzyme implicated in the cascade of events leading to plaque formation in Alzheimer's disease, was found with a pyrrolidinone analogue.