sept.is.igi6 a-Crotonic Acid, a Soil Constituent io 45 



upon by numerous investigators (7) and are represented by the following 

 formulae : 



CH 3 .CH CH 3 .CH 



« II 



HC.COOH HOOC.CH 



a-crotonic acid /3-crotonic acid 



Heretofore the occurrence in nature of crotonic acid has not been 

 firmly established, and the formation in soils of a compound possessing 

 such unusual chemical properties and structure is very difficult to explain. 

 Schlippe (6) described an acid from croton oil which had the formula 

 C 4 H 6 2 and to which he gave the name "crotonic acid," but later inves- 

 tigations (2) on this oil have failed to show the presence of crotonic acid. 

 /3-Hydroxybutyric acid, which is present in diabetic urine, is readily 

 converted into a-crotonic acid by heating either alone or with dilute 

 sulphuric acid (5). 



a-Crotonic acid is also produced from allyl cyanid, which is a constitu- 

 ent of mustard oil. Kramer and Grodzki (3) have isolated crotonic and 

 isocrotonic acids from pyroligneous acid obtained by the dry distillation 

 of wood. 



These methods of obtaining a-crotonic acid suggest the possibility of 

 its formation in soils during the destruction of cellulose, from /3-hydroxy 

 acids of the aliphatic series, or by the hydrolysis of allyl cyanid, which 

 is found in the essential oils from certain plants. 



LITERATURE CITED 



(1) Bulk, Carl. 



1866. Ueber Crotonsaure. In Ann. Chem. u. Pharm., Bd. 139 (n. R. Bd. 63), 

 Heft 1, p. 62-70. 



(2) KekulE, Aug. 



1872. Ueber einige Condensationsproducte des Aldehyds. In Ann. Chem. u. 

 Pharm., Bd. 162 (n. R. Bd. 86), Heft 1, p. 77-124; Heft 2/3, p. 309-320. 



(3) Kramer, G., and Grodzki, M. 



1878. Ueber die Sauren des Holzessigs und den Zusammenhang derselben mit 

 den sogenannten Holzolen. In Ber. Deut. Chem. Gesell., Jahrg. 11, 



P- ^35 6 ~ l 3 62 - 



(4) MorrELL, R. S., and Hanson, E. K. 



1904. Studies on the dynamic isomerism of a- and /3-crotonic acids. Part 1. 

 In Jour. Chem. Soc. [London], Trans., v. 85, pt. 2, p. 1520-1526. 



(5) Neuberg, Carl. 



1911. Der Harn ... T. 1. Berlin. 



(6) Schlippe, Thom. 



1858. Untersuchung des Crotonoles. In Ann. Chem. u. Pharm., Bd. 105 (n. R. 

 Bd. 29), Heft 1, p. 1-36. 



(7) Schmitz, Ernst. 



1911. Ungesattigte Sauren der aliphatischen Reihe. In Abderhalden, Emil. 

 Biochemisches Handlexikon. Bd. 1, Halfte 2, p. 1023-1052. 



(8) Van Duyne, Cornelius, and ByERS, W. C. 



1913. Soil survey of Harrison county, Texas. In U. S. Dept. Agr. Bur. Soils, 

 Adv. Sheets Field Operations 1912, 47 p., 1 fig., 1 pi. 



