Drumm — The Constitution of Catechin : Parti. 45 



with the fomiula 5-7-dimethoxy-2iiip-dimethoxy phciiyl-l'4-bei)zopyranol 

 anhydi'ohydroeliloiide. 



It is obvious that the formula (ill) assigned to dehydro catechin tetra- 

 methyl ether argues to either of the formulae (viii) or (ix) for cateehin 

 tetramethyl ether. 



VIII. IX. 



At the present stage, it does not seem easy to suggest a line of concise 

 experimental investigation such as would admit a final decision between the 

 above two formulae. 



The recent theory _of induced alternate polarities in carbon compounds 

 advanced by Eobinsou and Kermack (Jour. Chem. Soc, 1922, exxi, p. 427), 

 and independently by Lapworth (ibid., p. 416), and now somewhat generally 

 accepted as being at least a " useful system of classification of a wide range 

 of phenomena" in organic chemistry, suggests formula (ix) for the tetra- 

 methyl ether of catechin. This theory, at the same time, would emphatically 

 reject formula (viii), for in the latter formula the (-0H) group attached to 

 carbon atom (3) should exhibit a relatively large induced positive polarity 

 (as illustrated in the diagram) ; and it is unlikely that, in such a compound, 

 the hydroxy] group would be so easily replaced by the negative chlorine 

 atom, as is the case with catechin tetramethyl ether. In formula (ix), on 

 the other hand, the (-0H) group attached to carbon atom (4) should possess 

 a large induced negative polarity, and this would explain why catechin 

 tetramethyl ether so readily reacts with phosphorus pentaehloride, even at 

 ordinary temperatures. Furthermore, the behaviour of the chloride of 

 catechin tetramethyl ether towards ethyl and butyl alcohols rather 

 strengthens these conclusions. This chloride, when boiled for a short time 

 with ethyl or butyl alcohol, yields the corresponding ethyl and butyl catechin 

 tetramethyl ethers respectively. The analogy of such a reaction with that 

 between an acid chloride and an alcohol is seen from the particular example : 



+ J 



CH3-C— CI+ C,H,-0--H = CH3C- -OC.,H. + H--C1 



+ 

 A compound such as (CH3C0)C1, of course, represents the extreme type of 



negative CI. (Compare Lapworth, Mem. Manchester Phil. Soc, 1920, 



Ixiv (3), pp. 1-16.) 



