1904.] KELLER AND MAAS — DIMETHYL RACEMIC ACID. 105 



DIMETHYL RACEMIC ACID: ITS SYNTHESIS AND 

 DERIVATIVES. 



BY HARRY F. KELLER AND PHILIP MAAS. 



{Bead April 7, 1904.) 



In the course of an investigation on diacetyl, the simplest diket- 

 one of the aliphatic series, Fittig^ and one of us obtained a crystal- 

 lized acid of the composition CgH^oOg -f~ HjO, which they recog- 

 nized as a dimethyl derivative of racemic acid. Continuing the 

 work on diacetyl, we prepared the diketone on a larger scale, and 

 it occurred to us to utilize the accumulated residues for a more 

 extended study of dimethyl racemic acid. In view of the close 

 relationship and the striking resemblance which this compound 

 bears to the tartaric acids, and of certain interesting questions which 

 had been suggested in the original research, it seemed well worth 

 while to take up this line of work. Unfortunately the time we 

 could devote to it has been very limited, so that the results we have 

 to present are somewhat fragmentary, and much remains to be done. 



The conversion of diacetyl into the desired acid was effected by 

 the same process as that employed by Strecker in his well-known 

 synthesis of racemic acid, that is by successively treating the diket- 

 one with hydrocyanic and hydrochloric acids. Thus 



OH 



CH3— C — + HCN CH3 — C-CN 



CH3 — C — 0+HCN ~ CHo— C-CN 



OH 



OH OH 



/ ^ / 



^^3 —^~ ^^ + 4H.O + 2HCI = ^^3 — ^ — COOH ^ 2NH^C1 

 CH3 — C — CN " CH3 — C ~ COOH 



OH OH 



These reactions, consisting in the addition of hydrocyanic acid 

 to an aldehyde or ketone, followed by '' saponification " or hydro- 

 lysis of the resulting cyanhydrin, are regarded as generally appli- 

 cable to aldehydes and ketones and are, of course, familiar to every 



^ Liebig's Annalen der C/ie?nie, Vol. 249, p. 208. 



