150 



Proceciiiiigs of the Royal Irish Acudonij. 



chloride which readily loses hydrochloric acid when heated with pyridine. 

 The dehydvocatechin-tetramethylether, obtained in this way, interacted with 

 bromine to form a red monobromide which had the properties of an oxoninni 

 salt, and closely resembled the benzopyranol anhydrohydriodide prepared by 

 E. E. Watson and Senn (Jour. Chem. Soc, 1915, cvii, p. 1485), by the action 

 of magnesium-ethyl iodide on luteolin-tetraethylether. It was assumed 

 therefore that the red monobromide had the formula i, and deliydro- 

 eatechin-tetrametliylether tlie formula ir. 



OCH, 



OCHj 

 OCH, 



OCKa^^H 



ir. 



If these formulae were correct, catechin woukl be either in or iv, and it 

 would be easy to trace genetic relations between the catechins, the tlavones, 

 and the anthocyan pigments of plants (Cf. Eyan and Walsh, loe. cii.]. 



HO 



CH - 



CH„ 



.,OH 

 OH 



OH 



CHOH 



CH — 



CHOH 



OH 

 OH 



OH.. 



CH, 



HI. 



IV. 



E. Eobinson (private communication) has, however, prepared syntheti- 

 cally a substance to which the formula I has been given, and which is not 

 identical with the bromide of dehydrocatechiu-tetramethylether. It is 

 possible, therefore, tliat dehydroeatechiu-tetramethylether may be a benzyl- 

 coumarone derivative and possess the constitution represented liy forn-iula V: — 



O CH. 



C - CH^-/ \o C H, 



OCH, 



CH 



V. 



In order to test this point experimentally it was decided to prepare some 

 reductiori derivatives of veratrylidene-3'5-dimethoxy-coumaranone (vi) as well 

 as of dehydrocatechin-tetramethylether. 



The preparation of veratrylidene-ri'O-diinethoxycoumaranone has not been 

 described hitherto in the literature, it was obtained by us from \e)-atric 

 aldehyde and ^-o-diniethoxycouniarauone. The latter substance was first 



