_ NaS 
= 
aie 
eS 
Brieaberd, as in cartel experiments, reduced the petones with yeast, which was 
Peau’ in greater quantities than usual. Also only a yield of 10 per cent. of secondary 
alcohols was obtained. The reaction products, which could be isolated by treatment of 
“Notes ON SCIENTIFIC RESEARCH. | 135 
yak Leh ON aaa are Nl aaa lk kf aa a a i oh ATA NS a 1 Me 
3 Ee or "e ' 7 - ht elt, “ uy , ‘ eon . 
in’. : feat Wir rae As, é J : 
_ the unchanged ketone with sodium bisulphite or hydrazine bases, were regularly optically — 
active, and were mostly dextrorotatory. In no case were optically-pure alcohols formed; 
og ROR example, the rotation shown by methylethylcarbinol (prepared from metyietee 
- ketone) ({e] +3: 34°), was considerably higher than what R. Meth found for the secondary 
- butyl alcohol ([«]p + 0.329) which he had obtained by splitting the corresponding butyl- 
sulphuric atid by the alkaloid salt method. The fact that the ketones may be reduced 
to optically active secondary alcohols, proves that a true reduction process occurs, and 
_ possibly not a rearrangement in alcohol and acid. Since in all cases, as in the reduction 
of methylheptenone, considerable quantities of acetaldehyde appeared, it is to be assumed 
_ that during the course of the reaction, it is a.case of relationship between phytochemical 
- reduction and carbohydrate metabolism. 
Optically active alcohols are also obtained when racemic carninore are decomposed 
” 
: by fungus cultures. Whilst here, however, an antipode is removed by oxidation, Neuberg 
ee gets the alcohol by reduction of the ketone. Here the stage of the inactive form is. 
__ mot passed through; a carbinol appears that is richer in the optically active component 
than one obtained by the decomposition of racemic alcohols. _ 
Further the question was of interest, whether also compounds with more carbonyl — 
| - This result is not so surprising, when it is considered that diacetyl occurs in the 
volatile oils of higher plants,’ e.y. in savin, cypress oils, &c.; the diketone also is o ; 
importance in the metabolic processes of innumerable micro-organisms. 
This leaves the question undecided whether the reduction of diacetyl passed through 
the stage of the semihydrated diketone acetylmethylcarbinol; but according to the 
_ behaviour of benzil C;sH;COCOC,H;, it may be assumed to do so. Benzil, when bio- 
‘chemically reduced, yielded chiefly benzoin CsHsCHOHCOC,Hs;, but no hydrobenzoin. 
Smaller quantities of an optically active substance, probably /-benzoin, were attached 
to the benzoin. In the reduction of the~diketone also, in addition to the reaction 
products, an increased formation of acetaldehyde was demonstrated. 
By means of aniline-zinc-chloride ZnCl(NH>C.Hs), that had formerly been nointed out 
to act as a condensation agent between ketones and amines’), G.Reddelien and O. Meyn 
ies succeeded in obtaining condensation products of hydroaromatic ketones with aniline 
- and aniline derivatives as ‘per method of Schiff’s bases 3). 
Cyclohexanone heated for 20 minutes at 155° with aniline and a little phils ae 
chloride, gave a bright yellow oil of boiling point 140°, cyclohexanoneanil CeHio : NCeHs. | 
The oil easily changes by autocondensation into cyclohexylidene-2-cyclohexanoneanil 
‘ ~~ CeHyo: C.Hs:NC.Hs;, which is also obtained as chief product if the reaction between cyclo- 
hexanone, aniline and aniline-zinc-chloride is allowed to continue for a longer time 
(45 minutes) at 180°. Analogously menthone with aniline yielded menthoneanil, a yellow 
oil (b. p. 159 to 160° at 12 mm); with p-toluidine, menthone-p-toluil, a yellow oil 
(b. p. 178° at 16 mm); with p-anisidine, menthone-p-anisil (white crystals, m. p. 61.59). 
All these compounds were quickly oxidized in the air, and became dark coloured. 
2 sf 
i. 
4) Berl. Berichte 52 (1919), 2248. — %) Berl. Berichte 43 (1910), 2476. — 2) Berl. Berichte 58 (1920), 345. 
groups in the molecule, as diketones, could be biochemically hydrogenized’). It was found 
that diacetyl CH;COCOCH:, by the action of living yeast could be very easily converted 
into levorotatory 2,3- butylene-glycol CH;CHOHCHOHCH,, with a yield of 35 per cent. 
