150 Mr Mills, The Ketodilactone of Benzophenone, ete. : 
It was converted by heating with phosphoryl chloride and 
two molecular proportions of phosphorus pentachloride into the 
acid chloride C,;H,O,(COCI), (found Cl=18°86; C,H,O;Cl, — 
requires Cl= 18:83 per cent.), from which the esters of the keto- 
dilactone acid can be prepared. ‘The diethyl ester (ap. 212°) 
and the dibornyl ester (mM.p. 245°) have been prepared and — 
analysed. 
The acid is rapidly reduced by zinc dust and ammonia to 
benzhydrol-2-4-2’-4'-tetracarboxylic acid, which on liberation 
from its salts very rapidly passes into the lactone III. This 
compound (found C = 59:4; H =3:1; C,,H,,O, requires C = 596; 
H =2°9 per cent.) is considerably more soluble in acetic acid or 
alcohol than the ketodilactone and melts at 311°. Experiments 
on the resolution of these compounds have been commenced. 
In the preparation and investigation of the above-mentioned 
acid chloride and borny] ester of the ketodilactone I have had the 
valuable assistance of Mr A. F. R. Evans, B.A., of Pembroke College, 
to whom my best thanks are due. 
