TABLE 1.

¹⁹F NMR chemical shift values of fluorinated substrates and products

Compound	Chemical shift(s) (ppm)
2,3-Difluoro-4-hydroxybenzoate	−143.9 (F2), −167.4 (F3)
2,3-Difluorohydroquinone	−163.8
2,3-Difluoro-4-hydroxymuconic
semialdehyde	−129.7 (F2), −154.4 (F3)
enol-2,3-Difluoromaleylacete	−130.3 (F2), −154.0 (F3)
keto-2,3-Difluoromaleylacete	−129.0 (F2), −142.1 (F3)
2,5-Difluoro-4-hydroxybenzoate	−121.4 (F2), −146.9 (F5)
2,5-Difluorohydroquinone	−144.6
2,5-Difluoro-4-hydroxymuconic
semialdehydea	−110.7 (F2), −174.9 (F5)
3,5-Difluoro-4-hydroxybenzoate	−139.2
3,5-Difluorohydroquinone	−136.8

^aOr enol-2,5-difluoromaleylacetate.