Notes on scientific research. 



111 



hydrolysis by means of alkali into homocamphoric acid. This homocamphoric acid had 

 the m.p. 233° and the acid value 106 (calculated 107). 



The constitution of the polymerisation products of 1 : 2-cyc\ohexenones has not yet been 

 established with certainty. The opinion of Knoevenagel *) that these bodies probably 

 have the constitution of a /?-keto-alcohol of the type (I) is very improbable according 

 to Ruzicka, because a compound of this kind cannot be isolated in the case of the 

 saturated ketones, but yields at once, under loss of water, a dimolecular unsaturated 

 ketone (II). Ruzicka 8 ) showed that dimerides of c?/c?ohexenones form, with acetic acid: 

 anhydride, quantitatively monoacetates, so that the second oxygen atom would be bound 



CH 2 

 CHij/NcO 



H 2 C 



CH* 



ch 2 ! Jch— 



— c 



1 



\ JCH 2 



CH 2 



CH 2 



CH 2 OH CH 2 



(I) Unstable polymerisation product 

 of 1 : 2-ci/cZohexenone, Knoevenagel. 



CH</ >CO H 2 C/ X ,CH 2 

 CH 2 \ /C =Cv /CH S 

 CH 2 CH 2 



(II) Dimolecular unsaturated ketone. 



CH 2 CH CH< 



(III) First reaction product of the polymerisation. 



CH, 



CH 5 



(V) Biscarvon. 



in the hydroxyl group, and further that bis-1 : 3-methylc?/c/ , ohexenone has a double bond 

 in its molecule. These facts, as well as the observation, common in the case of 

 a : /5-unsaturated ketones, that additive combinations with reactfve methylene are not 

 taking place in the carbonyl group, but at the double bond of carbon atoms, led Ruzicka 

 to the conclusion that the first reaction-product to be considered in the polymerisation 

 of ci/dohexenones is a diketone of the formula (III). The further course of the poly- 

 merisation is indicated by the additive compound between acetic ester and c^/c/ohexenone, 

 as explained by Rabe and his collaborators 3 ). 1 Analogous to these processes studied 

 by Rabe there are, in the just-mentioned primary additive products (III), two possibilities 



•) Berl. Berichte 32 (1899), 423. 



2 ) Helvet. chim. acta 3 (1920), 781. — 3 ) Report October 1904, 126. 



