4 NOTES ON SCIENTIFIC RESEARCH. 91 
to study more accurately the conversion of borneol into camphene, H. Meerwein’*) 
examined pinacolin alcohols of monocyclic structure as to their behaviour in the 
process of splitting off water. He wanted to know above all whether the separation 
of water would also in these cases be accompanied by a change in the ring system. 
He investigated the course of the separation of water from the alcohols: 2,2-dimethyl 
eyclohexanol-1, 3-isopropyl-1, 1-methyl-c-oxethyleyclopentane and describes the prepa- 
ration of 1, 1-methylacetyleyclopentane. 
_ It would lead us too far to enter any further into this work, and we must be 
Satisfied with mentioning that the results of these laborious investigations form an 
excellent confirmation on an entirely new basis of Wagner’s formula for camphene. 
Regarding the §-glucoside of anisyl alcohol see page 79. 
Aldehydes. 
Reduction of aldehydes by means of yeast. 
On page 128 of our previous Report, we discussed a paper by Steenbock and 
Neuberg on the formation of higher alcohols from aldehydes by means of yeast. 
In the same way, Neuberg and E. Welde’) reduced benzaldehyde and phenylacet- 
aldehyde to the corresponding alcohols benzyl and phenylethyl alcohol by adding them 
to fermenting yeast. Benzaldehyde affords after a reaction of several days 22 to 27 p.c. 
of the theoretically possible quantity. As regards the reduction of phenylacetaldehyde, 
an acid reaction is best avoided by adding some calcium carbonate. In this manner 
24 g. of phenylacetaldehyde yielded 8,5 g. phenylethyl alcohol. 
_ As Neuberg and F. F. Nord’) proved, n-valeraldehyde can be easily reduced to 
n-amyl alcohol by means of fermenting yeast. This alcohol occurs in fusel oil. The 
authors determined its presence by oxidizing it into n-valeric acid, which was then 
identified by the properties of its calcium salt, as well as by its optical inactivity. 
In a similar manner, Neuberg and Nord as well as E. Rona‘) reduced n-capron- 
aldehyde to n-hexyl alcohol (b. ae 156 to 157°), and cinnamaldehyde to cinnamyl 
alcohol (b. p. 248 to 252°). 
An experiment to prepare synthetically «,6-hexenealdehyde has been mentioned 
on page 80 of this Report. 
Phenylacetaldehyde. in order to prepare this aldehyde, P. Jehl°) proceeds as 
follows: 16 g. methyl cinnamate are dissolved in 20 g. of methyl alcohol, and 10 g 
of bromine are added. The liquid congeals in the cold. Then a solution of 12 g 
sodium hydroxide in 24 g. of water is added under shaking, the temperature not being 
allowed to exceed 40°. After two hours, the mixture is neutralized with sulphuric acid, 
when the flocculent precipitate dissolves and an oil separates. After dilution to 250 cc., 
5,5 g. sodium carbonate are added, the phenylacetaldehyde is distilled with steam and 
the distillate extracted with ether. The yield amounts to 75 p.c. of what is calculated. 
If nitrocinnamic acid is treated in the same way, an aldehyde forms which smells like 
cinnamon. In order to explain this reaction it is supposed that at first dibromide 
1) Liebig’s Annalen 405 (1914), 129. — 2) Biochem. Zeitschr. 62 (1914), 477; Chem. Zentralbl. 1914, Il. 152. — 
*) Biochem. Zeitschr. 62 (1914), 482; Chem. Zentralbl. 1914, I]. 152. — +4) Biochem. Zeitschr. 67 (1914), 137. — 
*) Bull. Soc. ind. Mulhouse 88 (1913), 805; Journ. Soc. chem. Ind. 88 (1914), 333. 
