ie “ketone ecciiee’ “cAtiphat, and pinocamphone in its behaviour, which likewise 
Se possess a bridge. Pinocamphone for example, yields on oxidation with potassium 
aa permanganate a ketonic acid (pinonic acid) together with the dibasic isomeric camphoric 
3 : acids*). The rings of menthone, tetrahydrocarvone and thujone, on the contrary, which 
ce have 1 no bridges, were only split up between keto group and tertiary or quaternary u 
= carbon atom. Ketocineole, which is very stable in the presence of dilute acids, is 
~~ easily converted into dibromo- 1,8- pe Ocary one (VI)?) by ethereal hydrobromic Be 
sy = 
hee 1 
Serge e 
CHs CH; 
ie , | 
Hecj~ | 7 C—N-OH eG 2, § ~4C=N-No po! ~~ 60 
Ste Bee 
Be A Hic C(CHos ae . C(CH | oe 
oor SRS 4 oe see CH | CH 
(1) Ketocineole oxime. - (II) Pernitroso cineole. (IID) Ketocineole. 
Sr 7 CHe- CH, 
Sere 5 | 
ES GO; oe pake hen Sa eae ae CBr 
H.C a |60 ees COOH He ee CO 
ES ea are Le | 
esr [ C(CHe)s_ Chia), 
See CH 3 | cH 
© (IV) Homoterpenylic/ acid — -- (V) Cineolic acid. ie eS 
2 Ae 4 re aci ey (V) st aci | | BrC-(CH,). 
ae 7 ok he: 3 (V1) Dibromo-1, 8-tetrahydrocarvone. 
. 2 In his researches on the reduction products of hydroxymethylene camphor and : 
a + Methylene camphor, H. Rupe*) never succeeded in finding the second form, which - 
ought to have been formed during reduction in consequence of the freshly appearing 
¥ asymmetric carbon atom (I), On the contrary, Rupe, M. Sieberth and W. Kussmaul*) 
ae showed that amino-methylene camphor (II), (III) and. most of its derivatives can appear 
in two forms, in a low- -melting and usually easier soluble 6-form, ‘and in a higher 
; melting, and mostly more difficultly soluble «-form. With a few exceptions they can 
9 _ change from one form to the other (intramolecular rearrangement). Either both forms 
__ were equally stable, or when the one was more unstable than the other, it almost 
ie _ always happened to be the low-melting $form. The two derivatives of anthranilic 
de acid (IV) are especially interesting, for within quite small temperature differences one 
_ form is converted into the other. These intramolecular rearrangements occur spon- 
_ taneously on keeping, by light, and by means of higher boiling solvents, ‘&e. 
- Since a new asymmetric carbon atom does not appear, it is to be assumed that 
_ geometrical stereoisomerism is present (cis-trans-isomerism). A complete proof cannot 
yet be brought forward. Also no far-reaching conclusions could be drawn from the 
a optical examinations difficult owing to the great insolubility of the aminocamphor 
_ derivatives, since the amount of material for observation was too small. 
4) Liebig’s Annalen 846 (1906), 236. — %) Cf. also Report April 1915, 105. — *) Cf. Report 1919, 138. 
— +) Helvet. Chim. Acta 3 (1920), 50. As per kindly forwarded reprint. 
