Die Oxydation von Benzopyryliumsalzen zu Flavonolen

2,2′-Spirobis[chromene] Derivatives Chemistry and Their Relation with the Multistate System of Anthocyanins

“…6 The development of multistate/ multiresponsive systems, i.e., molecular reaction networks with several species which can be interconverted by different external stimuli such as light, heat, ions, or electrons (each state is a thermodynamic or kinetically trapped frame of the equilibria network), is a key point to systems chemistry with potential applications in several fields, namely molecular-level computing. 7−9 In spite of the numerous reported synthesis of 2,2′spirobis[chromene] derivatives, 10−13 in particular a few possessing hydroxyl substituents, 14,15 no studies in water or water−organic solvent mixtures have been reported, except the examples given in Schemes 2 6 and 3a. 16 The question is that the study of the anthocyanin type multistate that are intrinsic of 2,2′-spirobis[chromene] derivatives can only be highlighted in the presence of water.…”

“…In spite of the numerous reported synthesis of 2,2′-spirobis­[chromene] derivatives, − in particular a few possessing hydroxyl substituents, , no studies in water or water–organic solvent mixtures have been reported, except the examples given in Schemes and a . The question is that the study of the anthocyanin type multistate that are intrinsic of 2,2′-spirobis­[chromene] derivatives can only be highlighted in the presence of water.…”