— 165 — 



i-Pinol hydrate (m. p. 131°) very readily absorbs hydrogen, and in 

 doing so forms a compound Ci H 2 o0 2 (m. p. 139 to 140°) the constitution 

 of which has not yet been ascertained. As Wallach suspected it to be an 

 i-2, 8-menthanediol, the last-named alcohol was prepared synthetically, but 

 the mixture of the d- and 1-modifications of this 2, 6-menthanediol had a 

 melting point of 108 to 109 1 ). 



The ultimate product from d-carvone is 1-tetrahydrocarvone (b. p. 220 

 to 220,5°; d 20 o 0,9045; « D — 22°31'; [«] D — 24,88°; n D 1,4553; m. p. of the 

 semicarbazone 186 to 189°). 



Eucarvone is reducible to tetrahydroeucarvone, (b. p. 208 to 209°; 

 diso 0,9095; n D 1,4568) a body with an odour reminding of menthone. 



Hexahydro-p-acetyltoluene is obtainable in quantitative yield by reducing 

 J 3 -tetrahydro-p-acetyltoluene 2 ): b. p. 195 to 197°, di 8 o 0,9055, n D180 1,4509, 

 m. p. of the oxime 57 to 59°. It is also possible to start from z^-tetra- 

 hydro-p-acetyltoluene and to reduce the latter. 



Ctydohexenehexanone , when reduced with metallic sodium, yields 

 chiefly q/dohexenehexanol : m. p. 34 to 35°, b. p. 272 to 273°, m. p. of the 

 phenylurethane 118 to 119°. When oxidised with chromic acid it yields 

 a glycerol, and, as the principal product of conversion, a ketonic acid 

 C12H18O3 (m. p. 74 to 75°). When q/cfohexenehexanone is reduced by 

 Paal's method the resulting product is q/cZohexylhexanone, a saturated 

 ketone, Ci H 20 O with the following constants: b. p. 137° (12 mm), di 8 o 0,978, 

 "diso 1,4887, m. p. of the semicarbazone 203° (not very sharply), of the 

 oxime 100°, and of the benzylidene compound 100°. 



Thujone and a-thujaketonic acid were indifferent towards palladium 

 charged with hydrogen. Isothujone was reducible to thujamenthone: 

 b. p. 215 to 218°, di 9o 0,905, n D 1,4541; m. p. of the oxime 95°. 



/?-Thujaketonic acid (m. p. 78 to 79°) was reduced to its sodium salt, 

 the conversion giving rise to /?-acetyl-/?-£$opropylvaleric acid: m. p. of the 

 semicarbazone 140° (not very sharp). 



Thujaketone, when treated with hydrogen aud palladium chloride, is 

 converted into dihydrothujaketone. 



Methylheptenone is very readily reducible to methylheptanone (methyl- 

 isoamylacetone). This ketone boils at 164 to 165°: di 9o 0,8165, n D190 1,4144, 

 mol. refr. found 39,21, calc. as C 8 Hi 6 39,11. The m. p. of the semi- 

 carbazone is 157 to 158°. In contradistinction to methylheptenone, 

 methylheptanone shows very little tendency towards intramolecular 

 condensation. 



In the course of reducing «- and /?-fencholenic acid, the former acid 

 proved to be more readily reducible than the /?-acid. The ultimate products 

 of conversion were dihydro fencholenic acid and fencholic acid respectively. 



!) According to Rupe and Schlochoff (Berl. Berichte 38 [1905], 1722; Report October 

 1905, 112) 2, 8-menthanediol is prepared by shaking up dihydrocarveol with 35°/o sulphuric 

 acid, but according to Wallach it is more advantageous to use 3°/o acid. 



2 ) Comp. Report October 1910, 191. 



