126 — 



pounds which can be separated by crystallisation; with regard to the 

 structure nothing definite can be stated. On reducing, aminomenthol 

 is formed. Attemps to substitute in the latter the hydro xyl by bromine 

 were not successful. 



Carvone. Some time ago Paul Rabe und Karl Weilinger 1 ) 

 have demonstrated, that in attaching aceto -acetic ester to carvone by 

 means of sodium ethylate, and subsequent elimination of the carbethoxyl- 

 group, a dicyclic ketone alcohol, isopropylmethyl dicyclononanolone, is 

 formed. In a second treatise 2 ) on the subject in question, it is first 

 of all shown that the same compound can be obtained from chloro- 

 tetrahydrocarvonyl aceto -acetic ester (I), the condensation-product from 

 aceto-acetic ester, carvone and hydrochloric acid. By the action of zinc 

 dust, glacial acetic acid, and fuming hydrochloric acid on this substance, 

 a mixture is formed of dihydrocarvonyl aceto-acetic ester (II) and the 

 acetate of 8-oxyterpane-2-on-6-yl-aceto-acetic ester; melting point 133 

 from alcohol. 



COOC 2 H 5 



1 







COOC 9 H 5 

 1 





1 

 HC CH 



CTT 





1 



CH- 

 1 

 CO 



1 



CT-T 



ch 



. 1 1 

 CO CH. 



1 1 



1 7 CH 3 



CH 3 chcci<; 



1 X CH 3 



II. 



1 

 CH 



1 



ux 4 



CH 3 CH.Cf 



1 X CH 3 



CKL CO 



CEL 





CH„ 



CO- 



CH„ 





Dihydrocarvonyl aceto-acetic ester, a thick yellow oil, yields on 

 intramolecular aldol condensation with simultaneous elimination of the 

 carbethoxyl -group, a 1, 5-diketone, isopropenylmethyl dicyclonon- 

 anolone (III), 



CH 2 — CH CH 2 CH 2 — CH CH 2 



1 I I /7 CH 2 I I I 



III. CO CH.CH 3 CH.Cf IV. CH 2 CH . CH 8 CH . CH(CH 3 ) 

 I I I X CH 3 || . I 



CH 2 — COH CH 2 CH 2 — CH CH 2 



a red-brown oil, which on reduction is converted into the solid glycol 

 of the melting point 172 to 173 03 ). If the glycol is heated with 

 hydriodic acid to 220 , there is formed 3-isopropyl-9-methyl dicyck> 

 [i,3,3]nonane (IV). 



A ) Berl. Berichte 36 (1903), 225. — Report April 1903, 94. 



2 ) Berl. Berichte 37 (1904), 1667. 



3 ) Berl. Berichte 36 (1903), 230. — Report April 1903, 94. 



