Synthesis studies toward chloroazaphilone and vinylogous gamma-pyridones: two common natural product core structures.
Chloroazaphilone is a common structure found in a number of natural products. Reported herein is a practical synthesis of a model chloroazaphilone that utilizes Pb(OAc)4 oxidation of HClO4/HOAc pyrinium salt in a key one-pot operation. Reaction of this chloroazaphilone with various primary amines to afford the corresponding vinylogous gamma-pyridones was also fully investigated. The isolation of stable enamine intermediates provided direct evidence of reaction mechanisms.
Wei
Wan-Guo
WG
State Key Laboratory of Bioorganic and Natural Products Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 354 Fenglin Road, Shanghai 200032, China.
Yao
Zhu-Jun
ZJ
D001578:Benzopyrans / Q000737:chemistry; D001685:Biological Factors / Q000737:chemistry*; D002625:Chemistry, Organic / Q000379:methods; D015394:Molecular Structure; D010084:Oxidation-Reduction; D011728:Pyridones / Q000138:chemical synthesis*
D001578:Benzopyrans; D001685:Biological Factors; D011728:Pyridones; C501949:chloroazaphilone; C095348:isochromophilone VI; C101449:sclerotiorin