Ill 
because the alcohol expected is not formed in this case, but on the 
other hand the isomeric crystalline ortho-tolyl alcohol, whose boiling 
point almost coincides with that of phenyl ethyl alcohol (219°). The 
melting points of the phenyl urethanes of both alcohols also lie together 
(79° to 80°). 
According to Tiffeneau and Delange, the reaction proceeds as 
follows : 
CH^OMgCl CHgOH 
C,H,CH,MgCl + HCHO = C,H,<^ =C,H,/ 
CHg CH3 
+ H,0 
This abnormal influence on the reaction is said to be characteristic 
of formaldehyde which comes into application as trioxy methylene. 
Aldehydes. 
Citronellal. As a continuation of their work on the influence 
of the double-linking on the rotatory power of optically active substances, 
H. Rupe and W. Lotz^) have attempted to produce condensation- 
products of citronellal with acetic acid and acetone. It was then found 
that by the entrance of a double - linking in one of the four groups 
of the asymmetric carbon atom, the original dextrorotation of the 
aldehyde changes into Isevorotation ; whilst the combination of a double- 
linking with the carboxyl-group produces a powerful laevorotation, that 
with a carbonyl - group brings about a less powerful one. Citronel- 
lidene acetic acid, obtained by condensation of citronellal with malonic 
acid in the presence of pyridine, is an odourless, thick oil of the 
boiling point 175,5° to 177,5° (14 mm pressure). The physical constants 
are: d^ = 0,9326; a^^ = — 6,06°; [a]j-,= — 6,49°. The nickel, 
cobalt, and silver salts are suitable for analysis. The methyl ester of 
the acid, a colourless, fairly mobile liquid, has a characteristic and 
pleasant odour. It boils at 135° to 137° (14 mm pressure); d^=o,8i77; 
(in 9,72^/0 alcoholic solution) = — 0,76°; [a]j^ = — 9,56^. With 
aqueous hydrobromic acid the acid reacts with formation of an oily 
monohydrobromide. A dihydrobromide C^gHgaOgBrg, also oily, is 
formed with hydrobromic and glacial acetic acids. 
As a second condensation-product the authors obtained citronellal 
acetone, which of course was already known — if only in the patent 
literature. It is advisable to carry out the condensation by means 
of dilute caustic alkalis. The best way is to use for 20 gm. aldehyde, 
36 gm. acetone and 150 gm. of a i ^/q soda liquor. The mixture is 
^) Berliner Berichte 36 (1903), 2796. 
