103 
SYNTHESIS OF 2.3,3—TRIMETHYL CycLo-PENTANoNE, A CycLIc 
DERIVATIVE OF CAMPHOR. 
By W. A. Noyes. 
When a solution of the sodium derivative of methyl malonic ester and of the 
ethyl ester of y-bromisocaproic acid in absolute alcohol is boiled on the water 
bath, about six per cent. of the brom-ester is converted into the ethyl ester of 
2.3,3, tetramethyl-hexanoic 1, 2!, 6-acid, 
CO,C,H, 
CH, —C<¢o0,c.H. 
| 
CH = ‘ Y ) 
CH? > C— CH,CH,CO,C,H,. 
The free acid, obtained by saponification of the ester with caustic potash, 
loses carbon dioxide when heated to 200° and is converted into c—-33-trimethyl- 
adipic acid, CH, — CH —CO,H 
ois > C— CH, —CH,CO,H. When this acid is mixed with lime 
3 
and distilled, 2.3,3-trimethyl cyclopentanone, CH, — CH — CO 
| 
CH, 
| 
cH 0 CMe defosmedt uRne 
oxime of this ketone was proved to be identical with the oxime of the ketone ob- 
tained by J. W. Shepherd and myself from c—hydroxydihydrocis-campholytic 
acid. This synthesis establishes, beyond reasonable doubt, the correctness of 
Bouveault’s formula for camphor. 
CO— CH, 
| | 
CH“ 0)-6Hi 
| 
CH, 
| 
lala 
cH? > e — CH,. 
The details of the investigation appear in the American Chemical Journal, 
Vol. 23, p. 128. 
