— 94 — 



it yields the nitrile of perillic acid (b. p. 116 to 118° at 11 mm.; d 2 oo 0,9439; 

 Wd — 115°; n D 1,49775). The corresponding perillic acid has the following 

 constants: m. p. 130 to 131° (from dilute alcohol) b. p. 164 to 165° (10 mm.), 

 [«] D — 20° in 25°/o alcoholic solution, m. p. of the dibromide 166 to 167°. 



The foregoing shows that perillic aldehyde has for its basis the atomic 

 skeleton of limonene and that therefore a reducible double bond of the 

 aldehyde group is adjacent to it. As a matter of fact, by treating perillic 

 acid with sodium in an amylic alcohol solution, dihydroperillic acid, 

 CioH 16 2 , was obtained; m. p. 107 to 109°, b. p. 152 to 153° (10,5 mm.), 

 W D ±0°, m. p. of the dibromide 116 to 117°. The methyl ester boiled at 

 about 105 to 106° (11 mm.); d 19 o 0,9732, n D !,46768. Semmler reduced the 

 ester with sodium and alcohol by the usual method and obtained the di- 

 hydroperillic alcohol C 10 H 18 O: b. p. 114 to 115° (10 mm.), d i9 o 0,9284, 

 [«] D ±0°, n D 1,48191. This alcohol has a pleasant rose-like odour. 



The examination shows that perillic aldehyde is to be regarded as a 

 1 -methylal-4-isopropenyl hexene-1. 



CCHO 



H 2 C 



/ Ns 



CH 



H 2 C 



Ch 



CH 2 



1 



H3C CH 2 



perillic aldehyde. 



CHCOOH(CH 2 OH) 



H 2 cr x 



CH 2 



HsCl^/ 



CH 2 



CH 



H 3 C CH 2 



Dihy 



(Dihyd 



dro a 

 ro ale 



cid 

 ;ohol). 



H 2 C 



CCH 2 0H(CH 2 C1) 



^CH 



H 2 C 



Ch 



CH 2 

 1 



H 3 C CH 2 



perillic alcohole (chloride). 



H 2 C 

 H 2 C 



C-CHs 



CH 



CH 2 



CH 



H 3 C CH 2 



Limonene. 



Petitgrain Oil remains cheap at unaltered rates. Reliable qualities 

 have been offered in abundance and in Europe, as elsewhere, large stocks 

 are still in existence, the demand on the part of consumers having been 

 rather slack. We think ourselves justified in describing the market as very 

 neglected. 



