1. Improved Synthesis of Analogues of Red Wine Pyranoanthocyanin Pigments
- Author
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Cassio P. Silva, Renan Moraes Pioli, Gustavo T. M. Silva, Liu Liu, Mengjiao Zhang, Vânia M.T. Carneiro, Shasha Zheng, and Frank H. Quina
- Subjects
PROCESSOS QUÍMICOS ,Wine ,010405 organic chemistry ,Chemistry ,General Chemical Engineering ,Pyranoanthocyanin ,Substituent ,General Chemistry ,Chromophore ,010402 general chemistry ,Ring (chemistry) ,01 natural sciences ,Article ,0104 chemical sciences ,lcsh:Chemistry ,chemistry.chemical_compound ,Pigment ,lcsh:QD1-999 ,Computational chemistry ,visual_art ,Excited state ,visual_art.visual_art_medium - Abstract
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. (Tetrahedron Lett. 2008, 49, 6999–7004; Tetrahedron 2015, 71, 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.
- Published
- 2018