68 THE ALUMNI JOURNAL 



.Reychler (Bull. Soc. cliim., [3], 15, 364) is in agreement with 

 Barrier (Compfcs Rend., 117, 120) in the view that it is impossible 

 to derive a monochlorinated compound from geraniol. He endeav- 

 ored to obtain it by heating the dichloro derivative with water. 

 When he tried to fix exactly one molecule of hydrogen chloride on 

 geraniol, he obtained a mixture of products containing oxygen. 



TiEMANN and Semmler (Ber., 31, 832), by the action of alcoholic 

 potash on the chloro derivative of Jacobsen, observed the formation, 

 among other products, of inactive linalool, accompanied by geraniol. 

 The authors, whose work we have just briefly summarised, stud- 

 ied the direct action of hydrogen chloride on the alcohols, in the ab- 

 sence of a solvent. As a general rule they give no indication as to 

 the temperature of the reaction. It is by taking these conditions 

 into account that we have been able to obtain different results from 

 theirs, as will be seen. 



We have studied the action of hydrogen chloride gas oh linalool 

 and geraniol dissolved in their own weight of dry toluene, at various 

 temperatures ranging from 0° to 100° C. 



For these two alcohols, and for the same temperature, the external 

 signs of the reaction are the same. If a current of gaseous hydrogen 

 chloride be passed through a solution of linalool or geraniol in an 

 equal weight of dry toluene, cooled below 0° C, no liberation of 

 water is observed. It appears that there is either a solution pure 

 and simple of the gas or else a fixation by addition at the ethylenic 

 bonds. When a molecule of hydrogen chloride has thus been ab- 

 sorbed, and if the mixture be allowed to return to a temperature of 

 15° — 17° C, a cloudiness is seen to form rapidly and water is pre- 

 cipitated. After standing for some hours, if the water which is elim- 

 inated be weighed and allowance made for the increased weight due 

 to the hydrochloric acid dissolved in it, it will be found that this 

 quantity of water is less than that which would correspond with 

 thetotal replacement of an OH group by chlorine. The product of 

 the reaction is therefore complex ; it probably comprises, side by 

 side with a certain proportion of hydrochloric ester, some addition 

 products. We shall return to this point later. 



If the operation be carried out at a temperature of 100° C, its 

 course is quite different. The reaction is much sharper and yields 

 a single product, or at any rate one containing only a little of the 

 alcohol which may have escaped the reaction, and compounds 

 formed by secondary reactions. 



