486 Drushel and Dean — Hydrolysis of Esters of 



Art. XLI. — On the Hydrolysis of Esters of Substituted 

 Aliphatic Acids ; by W. A. Drushel and E. W. Dean. 



[Contributions f roni the Kent Chemical Laboratory of Yale Univ. — ccxliv.] 



5. Ethyl Esters of Lactic Acid, Glyceric Acid, (x-Ethy- 

 loxy and /3-ethyloxy propionic acids. 



Prelim in ary Disc uss ion. 



In a preceding paper* we announced our intention of contin- 

 uing a study of the effect of substituted hydroxy] groups on 

 the velocity of hydrolysis in acid solution. The substance 

 first studied in this connection was ethyl glycollate, which was 

 found to react somewhat more rapidly than ethyl acetate. 

 Three alkyloxy acetates were also studied, and here a retarda- 

 tion was found to occur. This eifect increases with the size 

 of the substituted group, but the difference is less between the 

 last two than between the first two members of the series. 



The esters we proposed to consider next were the alpha 

 hydroxy propionate (lactate), the beta hydroxy propionate 

 (hydracrylate), and the alpha, beta, dihydroxy ester (gly cerate). 

 After a considerable amount of work we have as yet been 

 unable to discover any practical method of preparing pure 

 ethyl hydracrylate in sufficient quantity for our use. Experi- 

 ments toward that end are still in progress and we hope to be 

 able to give an account of them in a future paper. We have, 

 however, been able to obtain some information as to the rela- 

 tive effect of alpha and beta positions of a substituted radical 

 by the determination of the velocity constants of the two ethyl- 

 oxy propionates. 



Preparation of the Esters. 



Ethyl lactate was obtained from The Hoffman & Kropff 

 Chemical Co. The ester was purified by fractional distillation 

 and a portion obtained for use which boiled at from 154*5° 

 to 155°. 



The preparation of ethyl glycerate was carried on as follows : 

 Calcium glycerate was obtained by oxidizing glycerine with nitric 

 acid in tubes,f neutralizing with calcium carbonate and recrys- 

 tallizing to purify the product. The acid was obtained by pre- 

 cipitating the calcium with the theoretical amount of oxalic acid, 

 filtering and evaporating to dryness by keeping for several days 

 on the steam bath. From this the ester was obtained by Frankland 

 and McGregor's 'f modification of the method of Henry.§ The 



* This Journal, xxxiv, 293. -f Mulder, Ber., ix, 1902. 



}Proc. Chem. Soc, lxiii, 512. §Ber., iv, 706. 



