Oxidative intramolecular [4 + 2]cycloaddition of silylene-protected 2-pyridone derivatives—a short and efficient synthesis of the DEF-ring of fredericamycin A
Oxidative intramolecular [4 + 2]cycloaddition of silylene-protected 2-pyridone derivatives—a short and efficient synthesis of the DEF-ring of fredericamycin A
Oxidative intramolecular [4 + 2]cycloaddition of silylene-protected 2-pyridone derivatives—a short and efficient synthesis of the DEF-ring of fredericamycin A
Thermal treatment of 2-pyridone derivatives 2 with dimethyldichlorosilane, triethylamine and chloranil in benzene gives 8-hydroxyisoquinolones 4 in high yields by oxidative intramolecular [4 + 2]cycloaddition which are used in the synthesis of the fully functionalized DEF-ring 14 of fredericamycin A.