256 SCIENCE PROGRESS 



to sunlight, hydrobenzoin and isohydrobenzoin are formed by 

 simple addition, 1 thus : 



C 6 H 5 CHO + C 6 H 5 CH 2 . OH = C 6 H 5 CH(OH) . CH(OH) . C 6 H 5 



but the action in this direction is far from quantitative and some 

 resin is formed. 



Benzophenone and benzylic alcohol interact in a rather more 

 complex way 1 ; the main product is benzopinacone, formed as 

 follows : 



2C 6 H 5 . CO . C 6 H 5 + QHsCH, . OH = (C 6 H 5 ) 2 C(OH) . C(OH)(C 6 H s ). 2 + C 6 H 5 . CHO; 



the benzaldehyde formed resinifies in part and is in part con- 

 verted into hydrobenzoins as above. In addition to these 

 changes, however, benzylic alcohol and benzophenone also give 

 rise to triphenylglycol : 



C.H^> C0 + QH 5 . CH 2 . OH = £ 6 g;>C(OH) . CH <§£** 



Triphenylglycol. 



As formic acid is so readily oxidised to carbon dioxide by 

 quinone in sunlight, it might be anticipated that benzophenone 

 would effect a similar change ; such, however, is not the case. 



The action of ethylic alcohol on alloxan is very striking, 1 

 alloxantin separating in quantity after a few weeks, the yield 

 after several months amounting to 35 per cent. Aldehyde is 

 also formed, the interaction being similar to that of quinone 

 and alcohol in which quinhydrone is formed ; the analogy is 

 strengthened by the fact that, according to Piloty and Finckh, 2 

 alloxantin has not the structure that is generally assigned to it, 



CO <NH '. 88> C (° H > • C(OH)<gO ; ™>CO 



but bears to alloxan the relation that quinhydrone bears to 

 quinone. The change may therefore be written : 



2CO <Nh'.CO> co + C,H fi O = C 2 H 4 + 



co <Sh:c8> c (° h )- -<c ( o oh) :Sh>co 



Alloxantin. 



In many of the changes above considered in which alcohol 

 plays a part, moist ether can be substituted for the alcohol with 



1 Atti R.Accad. Lincei, 1903, 12, i. 235 ; Ber. 1903,36, 1575 and 1953. 

 3 Annalen, 1904, 333, 22. 



