152 Proeeedinfjs of the Royal Irish Academij. 



ExPERDfENTAL. 



A. — liedudion of Dehydrocalechin-ietramethyleUier Dcoxi/ratccliin- 

 ietram ethyletlier. 



Dehytlrocaleclnu-telrametliylether, prepared by the method already 

 described by one of us (J. J. Druinni, Proc. Eoyal Irish Acad., 1923, xxxvi, B, 

 p. 47) from the chloride of eatechin-tetrametliylether, was reduced by 

 hydrogen in the presence of platinum black. 



The platinum black required for the experiment was prepared by 

 reduction of ehloroplatinie acid with potash and formaldehyde at a 

 temperature below 5^ C. (E. Willstaetter, Ber. Dtsch. Chem. Ges., 1921, liv, 

 p. 113). To render the platinum insolirble before' filtering it, a few drops of 

 acetic acid were added to the mixture (Feulgen, ibid., p. 360). The platinum 

 black was dried for fortj'-eight hours over sulphuric acid iu a desiccator. 



A solution of 2 g. of dehydrocatechui-tetrametlnlether in 50 c.c. of glacial 

 acetic acid was placed in a 200 e.c. flask, fitted witli an inlet and an outlet tube, 

 and 2 g. of platinum black were added. After expelling the air from the 

 flask by a current of pure hydrogen, the outlet tube was connected with a 

 manometer, and the flask was kept shaking until about 150 c.c. of hydrogen 

 had been absorbed. The theoretical volume of hydrogen required for the 

 saturation of the double bond in the amount of dehydrocatechin-tetramethyl- 

 ether taken is 127 c.c. 



The contents of the flask were filtered and the filtrate was diluted witli 

 twice its volume of water. Needle-shaped crystals separated and these were 

 reerystallised three times from boiling alcohol. The purified product melted 

 at 136-137' C. (corr.). It cannot be identical with dehydroeatechin- 

 tetramethylether, since a mixture of it with the latter substance melted about 

 1 20^ C. Ou analysis it gave the following results : — 



01121 substance gave 0-3586 CO, and 0-0852 H,0, corresponding to 



V, 68 82, H 6-65. 

 C„H.A requires C 6905, li 0-71. 



licojycalechin-litramcthyldhcr is insoluble in aqueous potash, and gives no 

 coloration with alcoholic ferric chloride. Us solution in concentrated 

 sulpluuic acid ha.s a yellow colour. 



Vk — rrei)arution of Va-atryliclene-o o-diiiielhoxycouiiiaranone. 



1. ?)-o-Ddiydroa;ycotim>iranaiic. 



About 40 g. of anhydrous phloroglucinol were dissolved in 1^00 c.c. of dry 

 ether and 24 g. of chloracotouitrile, prepared from chloracetaniide and 

 pliosphorus pentoxide by the nietliod of Scholl (I'.ei-. Dtsch. Cheni. Ges., 1896, 



