1 research outputs found
Improved Synthesis of Analogues of Red Wine Pyranoanthocyanin Pigments
An improved procedure
is described for the preparation of pyranoflavylium
cations from the reaction of 5,7-dihydroxy-4-methylflavylium cation
with aromatic aldehydes. Modifications of the procedure of Chassaing
et al. (<i>Tetrahedron Lett</i>. <b>2008</b>, <i>49</i>, 6999–7004; <i>Tetrahedron</i> <b>2015</b>, <i>71</i>, 3066–3078) circumvent the
reported restriction to electron-rich benzaldehydes and provide access
to a wide variety of substituted pyranoflavylium cations, including
those with electron-withdrawing substituents or an attached heterocyclic
or polycyclic aromatic ring. This opens the way for studies of substituent
and structural effects on the ground and excited states of these pyranoanthocyanin
analogues, the behavior of which should mirror fundamental aspects
of the chemistry and photophysics of the pyranoanthocyanin chromophores
present in mature red wines