JACKSON AND GRINDLEY. — ACETALS FROM QUINONES. 421 



that hydriodic acid converts it into a substance probably having the 

 formula C6Cl20C2H50H(OCOC6H5)o and melting at 164°, but we 

 have not yet studied this substance thoroughly enough to advance any 

 theory in regard to its constitution. Aniline also forms one or more 

 compounds with the saponification product, which we have not yet 

 succeeded in bringing it into a state fit for analysis. We must content 

 ourselves, therefore, at present with this preliminary statement of our 

 experiments on this subject, the study of which will be continued in 

 this laboratory during the next academic year. 



The methyl compounds CgC]o(OCH3)2(OCH3)2(OCOC6H5)o, melt- 

 ing at 193°, and C6Cl2(OCH3),(OCOC6H5)20, melting at 205°-206°, 

 which agree with the corresponding ethyl compounds in every respect, 

 have also been prepared. In order to determine whether other acid 

 radicals would act like benzoyl we treated the sodium salt of the 

 -diethyl hemiacetal with chlorocarbonic ester, and obtained the dichlor- 

 diethoxyquinone diethylacetaldicarbonic ester 



CeClaCOQHs) (OC2H5)2(OCOOCo 115)2 , 



which melts at 122°— 123°. In view of our experiments with the 

 benzoyl derivative, the saponification of this substance promises inter- 

 •esting results. 



We have tried a number of experiments to determine the limits of 

 the formation of hemiacetals from quinones ; and have found that the 

 dibromdiphenoxyquinone, melting point 266°-267°, made from brom- 

 anil, forms a hemiacetal, which seems to be as stable as the one 

 made from chloranil. The chlordiphenoxyquinone, melting point 

 169°-170°, made from trichlorquinoue, also forms a hemiacetal, but this 

 is much less stable than that containinor two atoms of chlorine. Even 

 the diraethoxydiphenoxyquinone yielded a hemiacetal, but it was so 

 unstable that it decomposed spontaneously almost as soon as it was 

 formed. So that the stability of the hemiacetals seems to depend on 

 the number and strength of the negative radicals attached to the 

 benzol ring. It was not very probable, therefore, that a hemiacetal of 

 quinone itself could be isolated, but yet we felt it was necessary to try 

 the experiment ; and this has established the fact that quinone is acted 

 on by sodic ethylate, although the product — a green salt — has so far 

 resisted our attempts to purify it for analysis. Work with it is 

 especially hard because of its very slight stability ; it takes fire 

 spontaneously, if dried in the air at ordinary temperatures ; and 

 although, if dried first in hydrogen, it does not take fire on mere ex- 

 posure to the air, it glows like tinder when heated to temperatures as 



