Ryan and Walsh — On Desoxy-Hydrocatechin-Tetramethyl-Ether. 115 



leaves of many plants, and which was isolated from Saponaria officinalis by 

 G-. Barger, 1 was shown to be a glycoside of vitexin, a substance previously 

 obtained by A. ti. Perkin, 2 and which is closely related to the hypothetical 

 dihydroxy-catechol-tannin mentioned above. 



Moreover, as A. G. Perkin has shown that scoparin is probably mono- 

 methoxy-vitexin, the former substance should on this hypothesis be the 

 monomethylether of dihydroxy-catechol-tannin. 



Just as demethylated scoparin (norscoparin) may be regarded as the 



intermediate compound between catechol- tannin and the anthocyan cyanidin 



or the tiavonol quercetin, so vitexin may fulfil the same role for a phloba-taimin 



on the one hand, and the anthocyan pelargonidin or the tiavonol kaempferol 



on the other hand. 



/ 0H 



HO/\/\CH . C 6 H 4 . OH HO/\/\C . CeHj . OH 



X/X/CHOH \/\/CHOH 



OH CH 2 OH CHOH 

 Hypothetical Vitexin. 



Phloba- Tannin. 



CI 



i 



HO,/\/\C . C 6 H 4 . OH HO^\^\C . C 6 H 4 . OH 



\/\/G . OH X/X/C . OH 



OH CO OH CH 



Kaempferol. Pelargonidin Chloride. 



The main objection to the formula of Perkin and Yoshitake is the fact 

 that catechin-tetramethylether forms with ease only a monobromo derivative, 

 aud that although catechin-tetramethylether can be oxidised to the quinone, 

 catechone-trimethylether, monobromo-catechin-tetramethylether cannot be 

 oxidised to a quinone. These reactions, which are difficult to interpret from 

 the chromane formula, are quite in accordance with the coumarane formula. 



Since the two formulae have been developed by analytical' methods, which 

 are in themselves not conclusive, we deemed it of interest to try to diserimi- 

 nate between them by a synthetical process. 



By energetical reduction of catechin-tetramethylether, von Kostanecki 



and Lampe 3 obtained an oily product which they termed desoxy-hydrocatechm- 



tetramethylether, and to which they assigned the formula 



OCH 3 

 CH 3 0/\ CH 3 0/\OH 



l N/ l CH 2 _-I X/ I CH2 . CH3 



OCH 3 



1 Journ. Chem. Soc, 1900, lxxxix., p. 1210. 



2 Juurn. Chem. Soc, 1900, lxxvii., p. 416. 



3 Ber. d. Deutsch. Chem. Ges., 1907, xl., p. 720. 



t 2 



