52 
3. either directly by isomerisation, or indirectly via the glycol, 
pass into an unsaturated primary alcohol: R.C=CH.R 
On. OH 
If acetic acid is also present, acetates may be formed either of 
the glycol, or of the unsaturated primary alcohol. 
In an aqueous solution we find with anethol and isosafrol a pretty 
exclusive and almost quantitative formation of the methylene ether. 
In an acetic solution in the presence of sulphuric acid both a 
diacetate and a methylene ether are formed, cedrene and camphene 
yield in these circumstances an acetate of an unsaturated, primary 
alcohol. 
Camphene, d. limonene and pinene yield in an acetic solution at 
the boiling-point of acetic acid likewise an acetate of an unsaturated 
alcohol besides other compounds with a higher boiling-point. 
The mutual reaction of formaldehyde, pinene and limonene causing 
the formation of an unsaturated primary alcohol has already been 
observed by Kriewitz’), who brought about a reaction of the com- 
ponents by heating them in the presence of alcohol at a high 
temperature. 
Prior to this, the formation of a primary, unsaturated alcohol has 
been ascertained by LADENBURG in the reaction between formaldehyde 
and a tetrahydropyridine-derivate. 
Except with the terpenes the condensation affords good results, 
ranging from 70°/, to 90°/,, of those theoretically possible; with the 
terpenes various products come into existence probably because the 
resulting unsaturated alcohol once more absorbs formaldehyde. 
The terpenes, containing more than one C = C group, there is besides 
a prior possibility of absorbing more than one molecule of formaldehyde. 
The author likewise observed the setting in of suchlike reactions with 
amylene, citronellol, methylheptenon, citronellal, undecylenic acid, 
aethyl-cinnamate. 
Experimental part. 
Styrol and formaldehyde. 
To a mixture of 33 gr. trioxymethylene and 320 gr. glacial acetic 
acid 32 gr. strong sulphuric acid was added, the trioxymethylene 
being solved by means of heating, then it was cooled down to 40° 
and while the mixture was shaken and occasionally refrigerated 104 gr. 
styrol was added in small quantities. If the temperature is allowed 
to rise beyond 50°, polymerization of the styrol sets in. The 
1) Ber. d. deutsch. chem. Ges. 31, 57. (1899). 
ibid, 32, 288, 2699 (1898). 
