Synthesis of Mono-, Di-, and Tri-3,4-dimethoxycinnamoyl-1,5-gamma-quinides

Tri-3,4-dimethoxycinnamoyl-1,5-γ-quinide was synthesized and fully characterized by a direct synthesis from quinic acid and a large excess of 3,4-dimethoxycinnamoyl chloride. Mono-and di-3,4-dimethoxycinnamoyl-1,5-γ- quinides were also obtained from the direct coupling of 1,5-γ-quinide and 3,4-dimethoxycinnamoyl chloride in different molar ratios. Moreover, a hypothetical mechanism of the direct lactonization is proposed. Mono-, di-, and tri-3,4-dimethoxycinnamoyl-1,5-γ-quinides have been synthesized from 1,5-γ-quinide and 3,4-dimethoxycinnamoyl chloride in different molar ratios. The only triester quinide was also easily obtained by a direct synthesis from D-(-)-quinic acid in the presence of an excess of the acyl chloride.