( 727 ) 



I have not been able to obtain the above raceniic urethane of 

 linaloöl by mixing d- and /-linaloöl and preparing the urethane from 

 this raeemic linaloöl ; nothing but an oil was formed, which could 

 not be brought to crystallise. Still, from each oil separately (c/-cori- 

 androl and /-linaloöl, the latter obtained from Schimmel & Co.) I 

 obtained the urethanes at once crystalline. In order to obtain raeemic 

 urethane, I was obliged to mix these urethanes of d- and /-linaloöl 

 in the proportion of their optical activity. The latter, however, had 

 not been determined ; in fact it was doubtful whether they were 

 optically active at all. Wai.baum and HCthig, who desired to prove 

 in this manner the identity of linaloöl dei-ived from different ethereal 

 oils, have overlooked the fact, that alcohols of such varying optical 

 activity as those found with linaloöl (from 1° to 35°) could not yield 

 the same phenyl-urethane. 



Raeemic urethane has generally quite another melting point than 

 the pure optically active substance. I was, therefore, obliged to fill 

 this void in their research. I found tliat the yield of crystallised 

 urethane, which only amounts to 157o, when one works according to 

 their directions (time of reaction one week), may be increased to 

 857o increase of the time to three months. The urethanes formed, 

 which all melt at 65° are optically active in proportion with the 

 optical activity of the alcohols started from. They consist of mixtures 

 of raeemic urethane (probably a raeemic compound) with the opti- 

 cally active component, which in a pure condition shows a rotation 

 of 23° 27' in a 200 mM. tube and has the m.p. 66°. The rotation 

 of pure optically active linaloöl under the same conditions may also 

 be calculated from this ; it then becomes 35° 27', whereas the highest 

 observed rotation of the natural substance amounts to 35° 14'. 

 This alcohol appears, thei-efore, to be very strongly subject to race- 

 misation, even in nature. By the facts stated it has, therefore, been 

 proved that linaloöl consists of a simple optically active terpene 

 alcohol ; the incorrectness of Barbier's formula for linaloöl and 

 myrcenol has been demonstrated, whilst the linaloöl formula of 

 TiEMANN and Semmler has received support. 



